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darling-JavaScriptCore/parser/Parser.cpp

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/*
* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2003-2019 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "Parser.h"
#include "ASTBuilder.h"
#include "BuiltinNames.h"
#include "DebuggerParseData.h"
#include "JSCJSValueInlines.h"
#include "VM.h"
#include <utility>
#include <wtf/Scope.h>
#include <wtf/SetForScope.h>
#include <wtf/StringPrintStream.h>
#define updateErrorMessage(shouldPrintToken, ...) do {\
propagateError(); \
logError(shouldPrintToken, __VA_ARGS__); \
} while (0)
#define propagateError() do { if (UNLIKELY(hasError())) return 0; } while (0)
#define internalFailWithMessage(shouldPrintToken, ...) do { updateErrorMessage(shouldPrintToken, __VA_ARGS__); return 0; } while (0)
#define handleErrorToken() do { if (m_token.m_type == EOFTOK || m_token.m_type & CanBeErrorTokenFlag) { failDueToUnexpectedToken(); } } while (0)
#define failWithMessage(...) do { { handleErrorToken(); updateErrorMessage(true, __VA_ARGS__); } return 0; } while (0)
#define failWithStackOverflow() do { updateErrorMessage(false, "Stack exhausted"); m_hasStackOverflow = true; return 0; } while (0)
#define failIfFalse(cond, ...) do { if (!(cond)) { handleErrorToken(); internalFailWithMessage(true, __VA_ARGS__); } } while (0)
#define failIfTrue(cond, ...) do { if (cond) { handleErrorToken(); internalFailWithMessage(true, __VA_ARGS__); } } while (0)
#define failIfTrueIfStrict(cond, ...) do { if ((cond) && strictMode()) internalFailWithMessage(false, __VA_ARGS__); } while (0)
#define failIfFalseIfStrict(cond, ...) do { if ((!(cond)) && strictMode()) internalFailWithMessage(false, __VA_ARGS__); } while (0)
#define consumeOrFail(tokenType, ...) do { if (!consume(tokenType)) { handleErrorToken(); internalFailWithMessage(true, __VA_ARGS__); } } while (0)
#define consumeOrFailWithFlags(tokenType, flags, ...) do { if (!consume(tokenType, flags)) { handleErrorToken(); internalFailWithMessage(true, __VA_ARGS__); } } while (0)
#define matchOrFail(tokenType, ...) do { if (!match(tokenType)) { handleErrorToken(); internalFailWithMessage(true, __VA_ARGS__); } } while (0)
#define failIfStackOverflow() do { if (UNLIKELY(!canRecurse())) failWithStackOverflow(); } while (0)
#define semanticFail(...) do { internalFailWithMessage(false, __VA_ARGS__); } while (0)
#define semanticFailIfTrue(cond, ...) do { if (UNLIKELY(cond)) internalFailWithMessage(false, __VA_ARGS__); } while (0)
#define semanticFailIfFalse(cond, ...) do { if (UNLIKELY(!(cond))) internalFailWithMessage(false, __VA_ARGS__); } while (0)
#define regexFail(failure) do { setErrorMessage(failure); return 0; } while (0)
#define failDueToUnexpectedToken() do {\
logError(true);\
return 0;\
} while (0)
#define handleProductionOrFail(token, tokenString, operation, production) do {\
consumeOrFail(token, "Expected '", tokenString, "' to ", operation, " a ", production);\
} while (0)
#define handleProductionOrFail2(token, tokenString, operation, production) do {\
consumeOrFail(token, "Expected '", tokenString, "' to ", operation, " an ", production);\
} while (0)
#define semanticFailureDueToKeywordCheckingToken(token, ...) do { \
if (strictMode() && token.m_type == RESERVED_IF_STRICT) \
semanticFail("Cannot use the reserved word '", getToken(token), "' as a ", __VA_ARGS__, " in strict mode"); \
if (token.m_type == RESERVED || token.m_type == RESERVED_IF_STRICT) \
semanticFail("Cannot use the reserved word '", getToken(token), "' as a ", __VA_ARGS__); \
if (token.m_type & KeywordTokenFlag) { \
if (!isAnyContextualKeyword(token)) \
semanticFail("Cannot use the keyword '", getToken(token), "' as a ", __VA_ARGS__); \
if (isDisallowedIdentifierLet(token)) \
semanticFail("Cannot use 'let' as a ", __VA_ARGS__, " ", disallowedIdentifierLetReason()); \
if (isDisallowedIdentifierAwait(token)) \
semanticFail("Cannot use 'await' as a ", __VA_ARGS__, " ", disallowedIdentifierAwaitReason()); \
if (isDisallowedIdentifierYield(token)) \
semanticFail("Cannot use 'yield' as a ", __VA_ARGS__, " ", disallowedIdentifierYieldReason()); \
} \
} while (0)
#define semanticFailureDueToKeyword(...) semanticFailureDueToKeywordCheckingToken(m_token, __VA_ARGS__);
namespace JSC {
std::atomic<unsigned> globalParseCount { 0 };
ALWAYS_INLINE static SourceParseMode getAsynFunctionBodyParseMode(SourceParseMode parseMode)
{
if (isAsyncGeneratorWrapperParseMode(parseMode))
return SourceParseMode::AsyncGeneratorBodyMode;
if (parseMode == SourceParseMode::AsyncArrowFunctionMode)
return SourceParseMode::AsyncArrowFunctionBodyMode;
return SourceParseMode::AsyncFunctionBodyMode;
}
template <typename LexerType>
void Parser<LexerType>::logError(bool)
{
if (hasError())
return;
StringPrintStream stream;
printUnexpectedTokenText(stream);
setErrorMessage(stream.toStringWithLatin1Fallback());
}
template <typename LexerType> template <typename... Args>
void Parser<LexerType>::logError(bool shouldPrintToken, Args&&... args)
{
if (hasError())
return;
StringPrintStream stream;
if (shouldPrintToken) {
printUnexpectedTokenText(stream);
stream.print(". ");
}
stream.print(std::forward<Args>(args)..., ".");
setErrorMessage(stream.toStringWithLatin1Fallback());
}
template <typename LexerType>
Parser<LexerType>::Parser(VM& vm, const SourceCode& source, JSParserBuiltinMode builtinMode, JSParserStrictMode strictMode, JSParserScriptMode scriptMode, SourceParseMode parseMode, SuperBinding superBinding, ConstructorKind defaultConstructorKindForTopLevelFunction, DerivedContextType derivedContextType, bool isEvalContext, EvalContextType evalContextType, DebuggerParseData* debuggerParseData, bool isInsideOrdinaryFunction)
: m_vm(vm)
, m_source(&source)
, m_hasStackOverflow(false)
, m_allowsIn(true)
, m_statementDepth(0)
, m_parsingBuiltin(builtinMode == JSParserBuiltinMode::Builtin)
, m_scriptMode(scriptMode)
, m_superBinding(superBinding)
, m_defaultConstructorKindForTopLevelFunction(defaultConstructorKindForTopLevelFunction)
, m_immediateParentAllowsFunctionDeclarationInStatement(false)
, m_debuggerParseData(debuggerParseData)
, m_isInsideOrdinaryFunction(isInsideOrdinaryFunction)
{
m_lexer = makeUnique<LexerType>(vm, builtinMode, scriptMode);
m_lexer->setCode(source, &m_parserArena);
m_token.m_location.line = source.firstLine().oneBasedInt();
m_token.m_location.startOffset = source.startOffset();
m_token.m_location.endOffset = source.startOffset();
m_token.m_location.lineStartOffset = source.startOffset();
m_functionCache = vm.addSourceProviderCache(source.provider());
m_expressionErrorClassifier = nullptr;
ScopeRef scope = pushScope();
scope->setSourceParseMode(parseMode);
scope->setIsEvalContext(isEvalContext);
if (isEvalContext)
scope->setEvalContextType(evalContextType);
if (derivedContextType == DerivedContextType::DerivedConstructorContext) {
scope->setConstructorKind(ConstructorKind::Extends);
scope->setExpectedSuperBinding(SuperBinding::Needed);
}
if (derivedContextType == DerivedContextType::DerivedMethodContext)
scope->setExpectedSuperBinding(SuperBinding::Needed);
if (strictMode == JSParserStrictMode::Strict)
scope->setStrictMode();
if (isModuleParseMode(parseMode))
m_moduleScopeData = ModuleScopeData::create();
if (isProgramOrModuleParseMode(parseMode))
scope->setIsGlobalCodeScope();
next();
}
class Scope::MaybeParseAsGeneratorForScope {
public:
MaybeParseAsGeneratorForScope(ScopeRef& scope, bool shouldParseAsGenerator)
: m_scope(scope)
, m_oldValue(scope->m_isGenerator)
{
m_scope->m_isGenerator = shouldParseAsGenerator;
}
~MaybeParseAsGeneratorForScope()
{
m_scope->m_isGenerator = m_oldValue;
}
private:
ScopeRef m_scope;
bool m_oldValue;
};
struct DepthManager : private SetForScope<int> {
public:
DepthManager(int* depth)
: SetForScope<int>(*depth, *depth)
{
}
};
template <typename LexerType>
Parser<LexerType>::~Parser()
{
}
template <typename LexerType>
Expected<typename Parser<LexerType>::ParseInnerResult, String> Parser<LexerType>::parseInner(const Identifier& calleeName, SourceParseMode parseMode, ParsingContext parsingContext, Optional<int> functionConstructorParametersEndPosition, const Vector<JSTextPosition>* classFieldLocations)
{
ASTBuilder context(const_cast<VM&>(m_vm), m_parserArena, const_cast<SourceCode*>(m_source));
ScopeRef scope = currentScope();
scope->setIsLexicalScope();
SetForScope<FunctionParsePhase> functionParsePhasePoisoner(m_parserState.functionParsePhase, FunctionParsePhase::Body);
FunctionParameters* parameters = nullptr;
bool isArrowFunctionBodyExpression = parseMode == SourceParseMode::AsyncArrowFunctionBodyMode && !match(OPENBRACE);
if (m_lexer->isReparsingFunction()) {
ParserFunctionInfo<ASTBuilder> functionInfo;
if (isGeneratorOrAsyncFunctionBodyParseMode(parseMode))
parameters = createGeneratorParameters(context, functionInfo.parameterCount);
else if (parseMode == SourceParseMode::ClassFieldInitializerMode)
parameters = context.createFormalParameterList();
else
parameters = parseFunctionParameters(context, parseMode, functionInfo);
if (SourceParseModeSet(SourceParseMode::ArrowFunctionMode, SourceParseMode::AsyncArrowFunctionMode).contains(parseMode) && !hasError()) {
// FIXME:
// Logically, this should be an assert, since we already successfully parsed the arrow
// function when syntax checking. So logically, we should see the arrow token here.
// But we're seeing crashes in the wild when making this an assert. Instead, we'll just
// handle it as an error in release builds, and an assert on debug builds, with the hopes
// of fixing it in the future.
// https://bugs.webkit.org/show_bug.cgi?id=221633
if (UNLIKELY(!match(ARROWFUNCTION))) {
ASSERT_NOT_REACHED();
return makeUnexpected("Parser error"_s);
}
next();
isArrowFunctionBodyExpression = !match(OPENBRACE);
}
}
if (!calleeName.isNull())
scope->declareCallee(&calleeName);
if (m_lexer->isReparsingFunction())
m_statementDepth--;
SourceElements* sourceElements = nullptr;
// The only way we can error this early is if we reparse a function and we run out of stack space.
if (!hasError()) {
if (isAsyncFunctionWrapperParseMode(parseMode))
sourceElements = parseAsyncFunctionSourceElements(context, parseMode, isArrowFunctionBodyExpression, CheckForStrictMode);
else if (isArrowFunctionBodyExpression)
sourceElements = parseArrowFunctionSingleExpressionBodySourceElements(context);
else if (isModuleParseMode(parseMode))
sourceElements = parseModuleSourceElements(context, parseMode);
else if (isGeneratorWrapperParseMode(parseMode))
sourceElements = parseGeneratorFunctionSourceElements(context, calleeName, CheckForStrictMode);
else if (isAsyncGeneratorWrapperParseMode(parseMode))
sourceElements = parseAsyncGeneratorFunctionSourceElements(context, parseMode, isArrowFunctionBodyExpression, CheckForStrictMode);
else if (parsingContext == ParsingContext::FunctionConstructor)
sourceElements = parseSingleFunction(context, functionConstructorParametersEndPosition);
else if (parseMode == SourceParseMode::ClassFieldInitializerMode) {
ASSERT(classFieldLocations && !classFieldLocations->isEmpty());
sourceElements = parseClassFieldInitializerSourceElements(context, *classFieldLocations);
} else
sourceElements = parseSourceElements(context, CheckForStrictMode);
}
bool validEnding = consume(EOFTOK);
if (!sourceElements || !validEnding)
return makeUnexpected(hasError() ? m_errorMessage : "Parser error"_s);
IdentifierSet capturedVariables;
UniquedStringImplPtrSet sloppyModeHoistedFunctions;
scope->getSloppyModeHoistedFunctions(sloppyModeHoistedFunctions);
scope->getCapturedVars(capturedVariables);
VariableEnvironment& varDeclarations = scope->declaredVariables();
for (auto& entry : capturedVariables)
varDeclarations.markVariableAsCaptured(entry);
if (isGeneratorWrapperParseMode(parseMode) || isAsyncFunctionOrAsyncGeneratorWrapperParseMode(parseMode)) {
if (scope->usedVariablesContains(m_vm.propertyNames->arguments.impl()))
context.propagateArgumentsUse();
}
CodeFeatures features = context.features();
if (scope->strictMode())
features |= StrictModeFeature;
if (scope->shadowsArguments())
features |= ShadowsArgumentsFeature;
if (m_seenTaggedTemplate)
features |= NoEvalCacheFeature;
if (scope->hasNonSimpleParameterList())
features |= NonSimpleParameterListFeature;
#if ASSERT_ENABLED
if (m_parsingBuiltin && isProgramParseMode(parseMode)) {
VariableEnvironment& lexicalVariables = scope->lexicalVariables();
const HashSet<UniquedStringImpl*>& closedVariableCandidates = scope->closedVariableCandidates();
for (UniquedStringImpl* candidate : closedVariableCandidates) {
// FIXME: We allow async to leak because it appearing as a closed variable is a side effect of trying to parse async arrow functions.
if (!lexicalVariables.contains(candidate) && !varDeclarations.contains(candidate) && !candidate->isSymbol() && candidate != m_vm.propertyNames->async.impl()) {
dataLog("Bad global capture in builtin: '", candidate, "'\n");
dataLog(m_source->view());
CRASH();
}
}
}
#endif // ASSERT_ENABLED
return ParseInnerResult { parameters, sourceElements, scope->takeFunctionDeclarations(), WTFMove(varDeclarations), WTFMove(sloppyModeHoistedFunctions), features, context.numConstants() };
}
template <typename LexerType>
template <class TreeBuilder> bool Parser<LexerType>::isArrowFunctionParameters(TreeBuilder& context)
{
if (match(OPENPAREN)) {
SavePoint saveArrowFunctionPoint = createSavePoint(context);
next();
bool isArrowFunction = false;
if (match(CLOSEPAREN)) {
next();
isArrowFunction = match(ARROWFUNCTION);
} else {
SyntaxChecker syntaxChecker(const_cast<VM&>(m_vm), m_lexer.get());
// We make fake scope, otherwise parseFormalParameters will add variable to current scope that lead to errors
AutoPopScopeRef fakeScope(this, pushScope());
fakeScope->setSourceParseMode(SourceParseMode::ArrowFunctionMode);
unsigned parametersCount = 0;
bool isArrowFunctionParameterList = true;
bool isMethod = false;
isArrowFunction = parseFormalParameters(syntaxChecker, syntaxChecker.createFormalParameterList(), isArrowFunctionParameterList, isMethod, parametersCount) && consume(CLOSEPAREN) && match(ARROWFUNCTION);
propagateError();
popScope(fakeScope, syntaxChecker.NeedsFreeVariableInfo);
}
restoreSavePoint(context, saveArrowFunctionPoint);
return isArrowFunction;
}
if (matchSpecIdentifier()) {
semanticFailIfTrue(!m_parserState.allowAwait && match(AWAIT), "Cannot use 'await' as a parameter name in an async function");
SavePoint saveArrowFunctionPoint = createSavePoint(context);
next();
bool isArrowFunction = match(ARROWFUNCTION);
restoreSavePoint(context, saveArrowFunctionPoint);
return isArrowFunction;
}
return false;
}
template <typename LexerType>
bool Parser<LexerType>::allowAutomaticSemicolon()
{
return match(CLOSEBRACE) || match(EOFTOK) || m_lexer->hasLineTerminatorBeforeToken();
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseSourceElements(TreeBuilder& context, SourceElementsMode mode)
{
const unsigned lengthOfUseStrictLiteral = 12; // "use strict".length
TreeSourceElements sourceElements = context.createSourceElements();
const Identifier* directive = nullptr;
unsigned directiveLiteralLength = 0;
auto savePoint = createSavePoint(context);
bool shouldCheckForUseStrict = mode == CheckForStrictMode;
while (TreeStatement statement = parseStatementListItem(context, directive, &directiveLiteralLength)) {
if (shouldCheckForUseStrict) {
if (directive) {
// "use strict" must be the exact literal without escape sequences or line continuation.
if (directiveLiteralLength == lengthOfUseStrictLiteral && m_vm.propertyNames->useStrictIdentifier == *directive) {
setStrictMode();
shouldCheckForUseStrict = false; // We saw "use strict", there is no need to keep checking for it.
if (!isValidStrictMode()) {
if (m_parserState.lastFunctionName) {
if (m_vm.propertyNames->arguments == *m_parserState.lastFunctionName)
semanticFail("Cannot name a function 'arguments' in strict mode");
if (m_vm.propertyNames->eval == *m_parserState.lastFunctionName)
semanticFail("Cannot name a function 'eval' in strict mode");
}
if (hasDeclaredVariable(m_vm.propertyNames->arguments))
semanticFail("Cannot declare a variable named 'arguments' in strict mode");
if (hasDeclaredVariable(m_vm.propertyNames->eval))
semanticFail("Cannot declare a variable named 'eval' in strict mode");
semanticFailIfTrue(currentScope()->hasNonSimpleParameterList(), "'use strict' directive not allowed inside a function with a non-simple parameter list");
semanticFailIfFalse(isValidStrictMode(), "Invalid parameters or function name in strict mode");
}
// Since strict mode is changed, restoring lexer state by calling next() may cause errors.
restoreSavePoint(context, savePoint);
propagateError();
continue;
}
// We saw a directive, but it wasn't "use strict". We reset our state to
// see if the next statement we parse is also a directive.
directive = nullptr;
} else {
// We saw a statement that wasn't in the form of a directive. The spec says that "use strict"
// is only allowed as the first statement, or after a sequence of directives before it, but
// not after non-directive statements.
shouldCheckForUseStrict = false;
}
}
context.appendStatement(sourceElements, statement);
}
propagateError();
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseModuleSourceElements(TreeBuilder& context, SourceParseMode parseMode)
{
TreeSourceElements sourceElements = context.createSourceElements();
SyntaxChecker syntaxChecker(const_cast<VM&>(m_vm), m_lexer.get());
while (true) {
TreeStatement statement = 0;
switch (m_token.m_type) {
case EXPORT_:
statement = parseExportDeclaration(context);
if (statement)
recordPauseLocation(context.breakpointLocation(statement));
break;
case IMPORT: {
SavePoint savePoint = createSavePoint(context);
next();
bool isImportDeclaration = !match(OPENPAREN) && !match(DOT);
restoreSavePoint(context, savePoint);
if (isImportDeclaration) {
statement = parseImportDeclaration(context);
if (statement)
recordPauseLocation(context.breakpointLocation(statement));
break;
}
// This is `import("...")` call or `import.meta` meta property case.
FALLTHROUGH;
}
default: {
const Identifier* directive = nullptr;
unsigned directiveLiteralLength = 0;
if (parseMode == SourceParseMode::ModuleAnalyzeMode) {
if (!parseStatementListItem(syntaxChecker, directive, &directiveLiteralLength))
goto end;
continue;
}
statement = parseStatementListItem(context, directive, &directiveLiteralLength);
break;
}
}
if (!statement)
goto end;
context.appendStatement(sourceElements, statement);
}
end:
propagateError();
for (const auto& pair : m_moduleScopeData->exportedBindings()) {
const auto& uid = pair.key;
if (currentScope()->hasDeclaredVariable(uid)) {
currentScope()->declaredVariables().markVariableAsExported(uid);
continue;
}
if (currentScope()->hasLexicallyDeclaredVariable(uid)) {
currentScope()->lexicalVariables().markVariableAsExported(uid);
continue;
}
semanticFail("Exported binding '", uid.get(), "' needs to refer to a top-level declared variable");
}
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseGeneratorFunctionSourceElements(TreeBuilder& context, const Identifier& name, SourceElementsMode mode)
{
auto sourceElements = context.createSourceElements();
unsigned functionKeywordStart = tokenStart();
JSTokenLocation startLocation(tokenLocation());
JSTextPosition start = tokenStartPosition();
unsigned startColumn = tokenColumn();
int functionNameStart = m_token.m_location.startOffset;
int parametersStart = m_token.m_location.startOffset;
ParserFunctionInfo<TreeBuilder> info;
info.name = &m_vm.propertyNames->nullIdentifier;
createGeneratorParameters(context, info.parameterCount);
info.startOffset = parametersStart;
info.startLine = tokenLine();
{
AutoPopScopeRef generatorBodyScope(this, pushScope());
generatorBodyScope->setSourceParseMode(SourceParseMode::GeneratorBodyMode);
generatorBodyScope->setConstructorKind(ConstructorKind::None);
generatorBodyScope->setExpectedSuperBinding(m_superBinding);
SyntaxChecker generatorFunctionContext(const_cast<VM&>(m_vm), m_lexer.get());
failIfFalse(parseSourceElements(generatorFunctionContext, mode), "Cannot parse the body of a generator");
popScope(generatorBodyScope, TreeBuilder::NeedsFreeVariableInfo);
}
info.body = context.createFunctionMetadata(startLocation, tokenLocation(), startColumn, tokenColumn(), functionKeywordStart, functionNameStart, parametersStart, strictMode(), ConstructorKind::None, m_superBinding, info.parameterCount, SourceParseMode::GeneratorBodyMode, false);
info.endLine = tokenLine();
info.endOffset = m_token.m_data.offset;
info.parametersStartColumn = startColumn;
auto functionExpr = context.createGeneratorFunctionBody(startLocation, info, name);
auto statement = context.createExprStatement(startLocation, functionExpr, start, m_lastTokenEndPosition.line);
context.appendStatement(sourceElements, statement);
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseAsyncFunctionSourceElements(TreeBuilder& context, SourceParseMode parseMode, bool isArrowFunctionBodyExpression, SourceElementsMode mode)
{
ASSERT(isAsyncFunctionOrAsyncGeneratorWrapperParseMode(parseMode));
auto sourceElements = context.createSourceElements();
unsigned functionKeywordStart = tokenStart();
JSTokenLocation startLocation(tokenLocation());
JSTextPosition start = tokenStartPosition();
unsigned startColumn = tokenColumn();
int functionNameStart = m_token.m_location.startOffset;
int parametersStart = m_token.m_location.startOffset;
ParserFunctionInfo<TreeBuilder> info;
info.name = &m_vm.propertyNames->nullIdentifier;
createGeneratorParameters(context, info.parameterCount);
info.startOffset = parametersStart;
info.startLine = tokenLine();
SourceParseMode innerParseMode = getAsynFunctionBodyParseMode(parseMode);
{
AutoPopScopeRef asyncFunctionBodyScope(this, pushScope());
asyncFunctionBodyScope->setSourceParseMode(innerParseMode);
SyntaxChecker syntaxChecker(const_cast<VM&>(m_vm), m_lexer.get());
if (isArrowFunctionBodyExpression) {
if (m_debuggerParseData)
failIfFalse(parseArrowFunctionSingleExpressionBodySourceElements(context), "Cannot parse the body of async arrow function");
else
failIfFalse(parseArrowFunctionSingleExpressionBodySourceElements(syntaxChecker), "Cannot parse the body of async arrow function");
} else {
if (m_debuggerParseData)
failIfFalse(parseSourceElements(context, mode), "Cannot parse the body of async function");
else
failIfFalse(parseSourceElements(syntaxChecker, mode), "Cannot parse the body of async function");
}
popScope(asyncFunctionBodyScope, TreeBuilder::NeedsFreeVariableInfo);
}
info.body = context.createFunctionMetadata(startLocation, tokenLocation(), startColumn, tokenColumn(), functionKeywordStart, functionNameStart, parametersStart, strictMode(), ConstructorKind::None, m_superBinding, info.parameterCount, innerParseMode, isArrowFunctionBodyExpression);
info.endLine = tokenLine();
info.endOffset = isArrowFunctionBodyExpression ? tokenLocation().endOffset : m_token.m_data.offset;
info.parametersStartColumn = startColumn;
auto functionExpr = context.createAsyncFunctionBody(startLocation, info, innerParseMode);
auto statement = context.createExprStatement(startLocation, functionExpr, start, m_lastTokenEndPosition.line);
context.appendStatement(sourceElements, statement);
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseAsyncGeneratorFunctionSourceElements(TreeBuilder& context, SourceParseMode parseMode, bool isArrowFunctionBodyExpression, SourceElementsMode mode)
{
ASSERT_UNUSED(parseMode, isAsyncGeneratorWrapperParseMode(parseMode));
auto sourceElements = context.createSourceElements();
unsigned functionKeywordStart = tokenStart();
JSTokenLocation startLocation(tokenLocation());
JSTextPosition start = tokenStartPosition();
unsigned startColumn = tokenColumn();
int functionNameStart = m_token.m_location.startOffset;
int parametersStart = m_token.m_location.startOffset;
ParserFunctionInfo<TreeBuilder> info;
info.name = &m_vm.propertyNames->nullIdentifier;
createGeneratorParameters(context, info.parameterCount);
info.startOffset = parametersStart;
info.startLine = tokenLine();
SourceParseMode innerParseMode = SourceParseMode::AsyncGeneratorBodyMode;
{
AutoPopScopeRef asyncFunctionBodyScope(this, pushScope());
asyncFunctionBodyScope->setSourceParseMode(innerParseMode);
SyntaxChecker syntaxChecker(const_cast<VM&>(m_vm), m_lexer.get());
if (isArrowFunctionBodyExpression) {
if (m_debuggerParseData)
failIfFalse(parseArrowFunctionSingleExpressionBodySourceElements(context), "Cannot parse the body of async arrow function");
else
failIfFalse(parseArrowFunctionSingleExpressionBodySourceElements(syntaxChecker), "Cannot parse the body of async arrow function");
} else {
if (m_debuggerParseData)
failIfFalse(parseSourceElements(context, mode), "Cannot parse the body of async function");
else
failIfFalse(parseSourceElements(syntaxChecker, mode), "Cannot parse the body of async function");
}
popScope(asyncFunctionBodyScope, TreeBuilder::NeedsFreeVariableInfo);
}
info.body = context.createFunctionMetadata(startLocation, tokenLocation(), startColumn, tokenColumn(), functionKeywordStart, functionNameStart, parametersStart, strictMode(), ConstructorKind::None, m_superBinding, info.parameterCount, innerParseMode, isArrowFunctionBodyExpression);
info.endLine = tokenLine();
info.endOffset = isArrowFunctionBodyExpression ? tokenLocation().endOffset : m_token.m_data.offset;
info.parametersStartColumn = startColumn;
auto functionExpr = context.createAsyncFunctionBody(startLocation, info, innerParseMode);
auto statement = context.createExprStatement(startLocation, functionExpr, start, m_lastTokenEndPosition.line);
context.appendStatement(sourceElements, statement);
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseSingleFunction(TreeBuilder& context, Optional<int> functionConstructorParametersEndPosition)
{
TreeSourceElements sourceElements = context.createSourceElements();
TreeStatement statement = 0;
switch (m_token.m_type) {
case FUNCTION:
statement = parseFunctionDeclaration(context, FunctionDeclarationType::Declaration, ExportType::NotExported, DeclarationDefaultContext::Standard, functionConstructorParametersEndPosition);
break;
case IDENT:
if (*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped) {
next();
failIfFalse(match(FUNCTION) && !m_lexer->hasLineTerminatorBeforeToken(), "Cannot parse the async function");
statement = parseAsyncFunctionDeclaration(context, ExportType::NotExported, DeclarationDefaultContext::Standard, functionConstructorParametersEndPosition);
break;
}
FALLTHROUGH;
default:
failDueToUnexpectedToken();
break;
}
if (statement) {
context.setEndOffset(statement, m_lastTokenEndPosition.offset);
context.appendStatement(sourceElements, statement);
}
propagateError();
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseStatementListItem(TreeBuilder& context, const Identifier*& directive, unsigned* directiveLiteralLength)
{
// The grammar is documented here:
// http://www.ecma-international.org/ecma-262/6.0/index.html#sec-statements
DepthManager statementDepth(&m_statementDepth);
m_statementDepth++;
failIfStackOverflow();
TreeStatement result = 0;
bool shouldSetEndOffset = true;
bool shouldSetPauseLocation = false;
switch (m_token.m_type) {
case CONSTTOKEN:
result = parseVariableDeclaration(context, DeclarationType::ConstDeclaration);
shouldSetPauseLocation = true;
break;
case LET: {
bool shouldParseVariableDeclaration = true;
if (!strictMode()) {
SavePoint savePoint = createSavePoint(context);
next();
// Intentionally use `isIdentifierOrAnyContextualKeyword(m_token)` and don't use `matchSpecIdentifier()`.
// We would like to fall into parseVariableDeclaration path even if "yield" is not treated as an Identifier.
// For example, under a generator context, matchSpecIdentifier() for "yield" returns `false`.
// But we would like to enter parseVariableDeclaration and raise an error under the context of parseVariableDeclaration
// to raise consistent errors between "var", "const" and "let".
if (!isIdentifierOrAnyContextualKeyword(m_token) && !match(OPENBRACE) && !match(OPENBRACKET))
shouldParseVariableDeclaration = false;
restoreSavePoint(context, savePoint);
}
if (shouldParseVariableDeclaration)
result = parseVariableDeclaration(context, DeclarationType::LetDeclaration);
else {
bool allowFunctionDeclarationAsStatement = true;
result = parseExpressionOrLabelStatement(context, allowFunctionDeclarationAsStatement);
}
shouldSetPauseLocation = !context.shouldSkipPauseLocation(result);
break;
}
case CLASSTOKEN:
result = parseClassDeclaration(context);
break;
case FUNCTION:
result = parseFunctionDeclaration(context);
break;
case IDENT:
if (UNLIKELY(*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped)) {
// Eagerly parse as AsyncFunctionDeclaration. This is the uncommon case,
// but could be mistakenly parsed as an AsyncFunctionExpression.
SavePoint savePoint = createSavePoint(context);
next();
if (UNLIKELY(match(FUNCTION) && !m_lexer->hasLineTerminatorBeforeToken())) {
result = parseAsyncFunctionDeclaration(context);
break;
}
restoreSavePoint(context, savePoint);
}
FALLTHROUGH;
case AWAIT:
case YIELD: {
// This is a convenient place to notice labeled statements
// (even though we also parse them as normal statements)
// because we allow the following type of code in sloppy mode:
// ``` function foo() { label: function bar() { } } ```
bool allowFunctionDeclarationAsStatement = true;
result = parseExpressionOrLabelStatement(context, allowFunctionDeclarationAsStatement);
shouldSetPauseLocation = !context.shouldSkipPauseLocation(result);
break;
}
default:
m_statementDepth--; // parseStatement() increments the depth.
result = parseStatement(context, directive, directiveLiteralLength);
shouldSetEndOffset = false;
break;
}
if (result) {
if (shouldSetEndOffset)
context.setEndOffset(result, m_lastTokenEndPosition.offset);
if (shouldSetPauseLocation)
recordPauseLocation(context.breakpointLocation(result));
}
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseVariableDeclaration(TreeBuilder& context, DeclarationType declarationType, ExportType exportType)
{
ASSERT(match(VAR) || match(LET) || match(CONSTTOKEN));
JSTokenLocation location(tokenLocation());
int start = tokenLine();
int end = 0;
int scratch;
TreeDestructuringPattern scratch1 = 0;
TreeExpression scratch2 = 0;
JSTextPosition scratch3;
bool scratchBool;
TreeExpression variableDecls = parseVariableDeclarationList(context, scratch, scratch1, scratch2, scratch3, scratch3, scratch3, VarDeclarationContext, declarationType, exportType, scratchBool);
propagateError();
failIfFalse(autoSemiColon(), "Expected ';' after variable declaration");
return context.createDeclarationStatement(location, variableDecls, start, end);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseDoWhileStatement(TreeBuilder& context)
{
ASSERT(match(DO));
int startLine = tokenLine();
next();
const Identifier* unused = nullptr;
startLoop();
TreeStatement statement = parseStatement(context, unused);
endLoop();
failIfFalse(statement, "Expected a statement following 'do'");
int endLine = tokenLine();
JSTokenLocation location(tokenLocation());
handleProductionOrFail(WHILE, "while", "end", "do-while loop");
handleProductionOrFail(OPENPAREN, "(", "start", "do-while loop condition");
semanticFailIfTrue(match(CLOSEPAREN), "Must provide an expression as a do-while loop condition");
TreeExpression expr = parseExpression(context);
failIfFalse(expr, "Unable to parse do-while loop condition");
recordPauseLocation(context.breakpointLocation(expr));
handleProductionOrFail(CLOSEPAREN, ")", "end", "do-while loop condition");
if (match(SEMICOLON))
next(); // Always performs automatic semicolon insertion.
return context.createDoWhileStatement(location, statement, expr, startLine, endLine);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseWhileStatement(TreeBuilder& context)
{
ASSERT(match(WHILE));
JSTokenLocation location(tokenLocation());
int startLine = tokenLine();
next();
handleProductionOrFail(OPENPAREN, "(", "start", "while loop condition");
semanticFailIfTrue(match(CLOSEPAREN), "Must provide an expression as a while loop condition");
TreeExpression expr = parseExpression(context);
failIfFalse(expr, "Unable to parse while loop condition");
recordPauseLocation(context.breakpointLocation(expr));
int endLine = tokenLine();
handleProductionOrFail(CLOSEPAREN, ")", "end", "while loop condition");
const Identifier* unused = nullptr;
startLoop();
TreeStatement statement = parseStatement(context, unused);
endLoop();
failIfFalse(statement, "Expected a statement as the body of a while loop");
return context.createWhileStatement(location, expr, statement, startLine, endLine);
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseVariableDeclarationList(TreeBuilder& context, int& declarations, TreeDestructuringPattern& lastPattern, TreeExpression& lastInitializer, JSTextPosition& identStart, JSTextPosition& initStart, JSTextPosition& initEnd, VarDeclarationListContext declarationListContext, DeclarationType declarationType, ExportType exportType, bool& forLoopConstDoesNotHaveInitializer)
{
ASSERT(declarationType == DeclarationType::LetDeclaration || declarationType == DeclarationType::VarDeclaration || declarationType == DeclarationType::ConstDeclaration);
TreeExpression head = 0;
JSTokenLocation headLocation;
TreeExpression tail = 0;
const Identifier* lastIdent;
JSToken lastIdentToken;
AssignmentContext assignmentContext = assignmentContextFromDeclarationType(declarationType);
do {
lastPattern = TreeDestructuringPattern(0);
lastIdent = nullptr;
JSTokenLocation location(tokenLocation());
next();
if (head) {
// Move the location of subsequent declarations after the comma.
location = tokenLocation();
}
TreeExpression node = 0;
declarations++;
bool hasInitializer = false;
failIfTrue(match(PRIVATENAME), "Cannot use a private name to declare a variable");
if (matchSpecIdentifier()) {
failIfTrue(match(LET) && (declarationType == DeclarationType::LetDeclaration || declarationType == DeclarationType::ConstDeclaration),
"Cannot use 'let' as an identifier name for a LexicalDeclaration");
semanticFailIfTrue(isDisallowedIdentifierAwait(m_token), "Cannot use 'await' as a ", declarationTypeToVariableKind(declarationType), " ", disallowedIdentifierAwaitReason());
JSTextPosition varStart = tokenStartPosition();
JSTokenLocation varStartLocation(tokenLocation());
identStart = varStart;
const Identifier* name = m_token.m_data.ident;
lastIdent = name;
lastIdentToken = m_token;
next();
hasInitializer = match(EQUAL);
DeclarationResultMask declarationResult = declareVariable(name, declarationType);
if (declarationResult != DeclarationResult::Valid) {
failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare a variable named ", name->impl(), " in strict mode");
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration) {
if (declarationType == DeclarationType::LetDeclaration)
internalFailWithMessage(false, "Cannot declare a let variable twice: '", name->impl(), "'");
if (declarationType == DeclarationType::ConstDeclaration)
internalFailWithMessage(false, "Cannot declare a const variable twice: '", name->impl(), "'");
ASSERT(declarationType == DeclarationType::VarDeclaration);
internalFailWithMessage(false, "Cannot declare a var variable that shadows a let/const/class variable: '", name->impl(), "'");
}
}
if (exportType == ExportType::Exported) {
semanticFailIfFalse(exportName(*name), "Cannot export a duplicate name '", name->impl(), "'");
m_moduleScopeData->exportBinding(*name);
}
if (hasInitializer) {
JSTextPosition varDivot = tokenStartPosition() + 1;
initStart = tokenStartPosition();
next(TreeBuilder::DontBuildStrings); // consume '='
propagateError();
TreeExpression initializer = parseAssignmentExpression(context);
initEnd = lastTokenEndPosition();
lastInitializer = initializer;
failIfFalse(initializer, "Expected expression as the intializer for the variable '", name->impl(), "'");
node = context.createAssignResolve(location, *name, initializer, varStart, varDivot, lastTokenEndPosition(), assignmentContext);
} else {
if (declarationListContext == ForLoopContext && declarationType == DeclarationType::ConstDeclaration)
forLoopConstDoesNotHaveInitializer = true;
failIfTrue(declarationListContext != ForLoopContext && declarationType == DeclarationType::ConstDeclaration, "const declared variable '", name->impl(), "'", " must have an initializer");
if (declarationType == DeclarationType::VarDeclaration)
node = context.createEmptyVarExpression(varStartLocation, *name);
else
node = context.createEmptyLetExpression(varStartLocation, *name);
}
} else {
lastIdent = nullptr;
auto pattern = parseDestructuringPattern(context, destructuringKindFromDeclarationType(declarationType), exportType, nullptr, nullptr, assignmentContext);
failIfFalse(pattern, "Cannot parse this destructuring pattern");
hasInitializer = match(EQUAL);
failIfTrue(declarationListContext == VarDeclarationContext && !hasInitializer, "Expected an initializer in destructuring variable declaration");
lastPattern = pattern;
if (hasInitializer) {
next(TreeBuilder::DontBuildStrings); // consume '='
TreeExpression rhs = parseAssignmentExpression(context);
propagateError();
ASSERT(rhs);
node = context.createDestructuringAssignment(location, pattern, rhs);
lastInitializer = rhs;
}
}
if (node) {
if (!head) {
head = node;
headLocation = location;
} else {
if (!tail) {
head = tail = context.createCommaExpr(headLocation, head);
recordPauseLocation(context.breakpointLocation(head));
}
tail = context.appendToCommaExpr(location, head, tail, node);
recordPauseLocation(context.breakpointLocation(tail));
}
}
} while (match(COMMA));
if (lastIdent)
lastPattern = context.createBindingLocation(lastIdentToken.m_location, *lastIdent, lastIdentToken.m_startPosition, lastIdentToken.m_endPosition, assignmentContext);
return head;
}
template <typename LexerType>
bool Parser<LexerType>::declareRestOrNormalParameter(const Identifier& name, const Identifier** duplicateIdentifier)
{
DeclarationResultMask declarationResult = declareParameter(&name);
if ((declarationResult & DeclarationResult::InvalidStrictMode) && strictMode()) {
semanticFailIfTrue(isEvalOrArguments(&name), "Cannot destructure to a parameter name '", name.impl(), "' in strict mode");
if (m_parserState.lastFunctionName && name == *m_parserState.lastFunctionName)
semanticFail("Cannot declare a parameter named '", name.impl(), "' as it shadows the name of a strict mode function");
semanticFailureDueToKeyword("parameter name");
if (!m_lexer->isReparsingFunction() && hasDeclaredParameter(name))
semanticFail("Cannot declare a parameter named '", name.impl(), "' in strict mode as it has already been declared");
semanticFail("Cannot declare a parameter named '", name.impl(), "' in strict mode");
}
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration) {
// It's not always an error to define a duplicate parameter.
// It's only an error when there are default parameter values or destructuring parameters.
// We note this value now so we can check it later.
if (duplicateIdentifier)
*duplicateIdentifier = &name;
}
return true;
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::createBindingPattern(TreeBuilder& context, DestructuringKind kind, ExportType exportType, const Identifier& name, const JSToken& token, AssignmentContext bindingContext, const Identifier** duplicateIdentifier)
{
ASSERT(!name.isNull());
ASSERT(name.impl()->isAtom() || name.impl()->isSymbol());
switch (kind) {
case DestructuringKind::DestructureToVariables: {
DeclarationResultMask declarationResult = declareVariable(&name);
failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare a variable named '", name.impl(), "' in strict mode");
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
internalFailWithMessage(false, "Cannot declare a var variable that shadows a let/const/class variable: '", name.impl(), "'");
break;
}
case DestructuringKind::DestructureToLet:
case DestructuringKind::DestructureToConst:
case DestructuringKind::DestructureToCatchParameters: {
DeclarationResultMask declarationResult = declareVariable(&name, kind == DestructuringKind::DestructureToConst ? DeclarationType::ConstDeclaration : DeclarationType::LetDeclaration);
if (declarationResult != DeclarationResult::Valid) {
failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot destructure to a variable named '", name.impl(), "' in strict mode");
failIfTrue(declarationResult & DeclarationResult::InvalidDuplicateDeclaration, "Cannot declare a lexical variable twice: '", name.impl(), "'");
}
break;
}
case DestructuringKind::DestructureToParameters: {
declareRestOrNormalParameter(name, duplicateIdentifier);
propagateError();
break;
}
case DestructuringKind::DestructureToExpressions: {
break;
}
}
if (exportType == ExportType::Exported) {
semanticFailIfFalse(exportName(name), "Cannot export a duplicate name '", name.impl(), "'");
m_moduleScopeData->exportBinding(name);
}
return context.createBindingLocation(token.m_location, name, token.m_startPosition, token.m_endPosition, bindingContext);
}
template <typename LexerType>
template <class TreeBuilder> NEVER_INLINE TreeDestructuringPattern Parser<LexerType>::createAssignmentElement(TreeBuilder& context, TreeExpression& assignmentTarget, const JSTextPosition& startPosition, const JSTextPosition& endPosition)
{
return context.createAssignmentElement(assignmentTarget, startPosition, endPosition);
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseArrowFunctionSingleExpressionBodySourceElements(TreeBuilder& context)
{
ASSERT(!match(OPENBRACE));
JSTokenLocation location(tokenLocation());
JSTextPosition start = tokenStartPosition();
failIfStackOverflow();
TreeExpression expr = parseAssignmentExpression(context);
failIfFalse(expr, "Cannot parse the arrow function expression");
context.setEndOffset(expr, m_lastTokenEndPosition.offset);
JSTextPosition end = tokenEndPosition();
TreeSourceElements sourceElements = context.createSourceElements();
TreeStatement body = context.createReturnStatement(location, expr, start, end);
context.setEndOffset(body, m_lastTokenEndPosition.offset);
recordPauseLocation(context.breakpointLocation(body));
context.appendStatement(sourceElements, body);
return sourceElements;
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::tryParseDestructuringPatternExpression(TreeBuilder& context, AssignmentContext bindingContext)
{
return parseDestructuringPattern(context, DestructuringKind::DestructureToExpressions, ExportType::NotExported, nullptr, nullptr, bindingContext);
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::parseBindingOrAssignmentElement(TreeBuilder& context, DestructuringKind kind, ExportType exportType, const Identifier** duplicateIdentifier, bool* hasDestructuringPattern, AssignmentContext bindingContext, int depth)
{
if (kind == DestructuringKind::DestructureToExpressions)
return parseAssignmentElement(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth);
return parseDestructuringPattern(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth);
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::parseObjectRestAssignmentElement(TreeBuilder& context)
{
JSTextPosition startPosition = tokenStartPosition();
auto element = parseMemberExpression(context);
if (!element || !context.isAssignmentLocation(element)) {
reclassifyExpressionError(ErrorIndicatesPattern, ErrorIndicatesNothing);
semanticFail("Invalid destructuring assignment target");
}
if (strictMode() && m_parserState.lastIdentifier && context.isResolve(element)) {
bool isEvalOrArguments = m_vm.propertyNames->eval == *m_parserState.lastIdentifier || m_vm.propertyNames->arguments == *m_parserState.lastIdentifier;
if (isEvalOrArguments && strictMode())
reclassifyExpressionError(ErrorIndicatesPattern, ErrorIndicatesNothing);
failIfTrueIfStrict(isEvalOrArguments, "Cannot modify '", m_parserState.lastIdentifier->impl(), "' in strict mode");
}
return createAssignmentElement(context, element, startPosition, lastTokenEndPosition());
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::parseAssignmentElement(TreeBuilder& context, DestructuringKind kind, ExportType exportType, const Identifier** duplicateIdentifier, bool* hasDestructuringPattern, AssignmentContext bindingContext, int depth)
{
TreeDestructuringPattern assignmentTarget = 0;
if (match(OPENBRACE) || match(OPENBRACKET)) {
SavePoint savePoint = createSavePoint(context);
assignmentTarget = parseDestructuringPattern(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth);
if (assignmentTarget && !match(DOT) && !match(OPENBRACKET) && !match(OPENPAREN) && !match(BACKQUOTE))
return assignmentTarget;
restoreSavePoint(context, savePoint);
}
JSTextPosition startPosition = tokenStartPosition();
auto element = parseMemberExpression(context);
semanticFailIfFalse(element && context.isAssignmentLocation(element), "Invalid destructuring assignment target");
if (strictMode() && m_parserState.lastIdentifier && context.isResolve(element)) {
bool isEvalOrArguments = m_vm.propertyNames->eval == *m_parserState.lastIdentifier || m_vm.propertyNames->arguments == *m_parserState.lastIdentifier;
failIfTrueIfStrict(isEvalOrArguments, "Cannot modify '", m_parserState.lastIdentifier->impl(), "' in strict mode");
}
return createAssignmentElement(context, element, startPosition, lastTokenEndPosition());
}
static const char* destructuringKindToVariableKindName(DestructuringKind kind)
{
switch (kind) {
case DestructuringKind::DestructureToLet:
case DestructuringKind::DestructureToConst:
return "lexical variable name";
case DestructuringKind::DestructureToVariables:
return "variable name";
case DestructuringKind::DestructureToParameters:
return "parameter name";
case DestructuringKind::DestructureToCatchParameters:
return "catch parameter name";
case DestructuringKind::DestructureToExpressions:
return "expression name";
}
RELEASE_ASSERT_NOT_REACHED();
return "invalid";
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::parseObjectRestElement(TreeBuilder& context, DestructuringKind kind, ExportType exportType, const Identifier** duplicateIdentifier, AssignmentContext bindingContext)
{
ASSERT(kind != DestructuringKind::DestructureToExpressions);
failIfStackOverflow();
TreeDestructuringPattern pattern;
if (!matchSpecIdentifier()) {
semanticFailureDueToKeyword(destructuringKindToVariableKindName(kind));
failWithMessage("Expected a binding element");
}
failIfTrue(match(LET) && (kind == DestructuringKind::DestructureToLet || kind == DestructuringKind::DestructureToConst), "Cannot use 'let' as an identifier name for a LexicalDeclaration");
semanticFailIfTrue(isDisallowedIdentifierAwait(m_token), "Cannot use 'await' as a ", destructuringKindToVariableKindName(kind), " ", disallowedIdentifierAwaitReason());
pattern = createBindingPattern(context, kind, exportType, *m_token.m_data.ident, m_token, bindingContext, duplicateIdentifier);
next();
return pattern;
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::parseObjectRestBindingOrAssignmentElement(TreeBuilder& context, DestructuringKind kind, ExportType exportType, const Identifier** duplicateIdentifier, AssignmentContext bindingContext)
{
if (kind == DestructuringKind::DestructureToExpressions)
return parseObjectRestAssignmentElement(context);
return parseObjectRestElement(context, kind, exportType, duplicateIdentifier, bindingContext);
}
template <typename LexerType>
template <class TreeBuilder> TreeDestructuringPattern Parser<LexerType>::parseDestructuringPattern(TreeBuilder& context, DestructuringKind kind, ExportType exportType, const Identifier** duplicateIdentifier, bool* hasDestructuringPattern, AssignmentContext bindingContext, int depth)
{
failIfStackOverflow();
m_parserState.assignmentCount++;
int nonLHSCount = m_parserState.nonLHSCount;
TreeDestructuringPattern pattern;
switch (m_token.m_type) {
case OPENBRACKET: {
JSTextPosition divotStart = tokenStartPosition();
auto arrayPattern = context.createArrayPattern(m_token.m_location);
next();
if (hasDestructuringPattern)
*hasDestructuringPattern = true;
bool restElementWasFound = false;
do {
while (match(COMMA)) {
context.appendArrayPatternSkipEntry(arrayPattern, m_token.m_location);
next();
}
propagateError();
if (match(CLOSEBRACKET))
break;
if (UNLIKELY(match(DOTDOTDOT))) {
JSTokenLocation location = m_token.m_location;
next();
auto innerPattern = parseBindingOrAssignmentElement(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth + 1);
if (kind == DestructuringKind::DestructureToExpressions && !innerPattern)
return 0;
failIfFalse(innerPattern, "Cannot parse this destructuring pattern");
context.appendArrayPatternRestEntry(arrayPattern, location, innerPattern);
restElementWasFound = true;
break;
}
JSTokenLocation location = m_token.m_location;
auto innerPattern = parseBindingOrAssignmentElement(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth + 1);
if (kind == DestructuringKind::DestructureToExpressions && !innerPattern)
return 0;
failIfFalse(innerPattern, "Cannot parse this destructuring pattern");
TreeExpression defaultValue = parseDefaultValueForDestructuringPattern(context);
propagateError();
context.appendArrayPatternEntry(arrayPattern, location, innerPattern, defaultValue);
} while (consume(COMMA));
consumeOrFail(CLOSEBRACKET, restElementWasFound ? "Expected a closing ']' following a rest element destructuring pattern" : "Expected either a closing ']' or a ',' following an element destructuring pattern");
context.finishArrayPattern(arrayPattern, divotStart, divotStart, lastTokenEndPosition());
pattern = arrayPattern;
break;
}
case OPENBRACE: {
auto objectPattern = context.createObjectPattern(m_token.m_location);
next();
if (hasDestructuringPattern)
*hasDestructuringPattern = true;
bool restElementWasFound = false;
do {
bool wasString = false;
if (match(CLOSEBRACE))
break;
if (match(DOTDOTDOT)) {
JSTokenLocation location = m_token.m_location;
next();
auto innerPattern = parseObjectRestBindingOrAssignmentElement(context, kind, exportType, duplicateIdentifier, bindingContext);
propagateError();
if (!innerPattern)
return 0;
context.appendObjectPatternRestEntry(m_vm, objectPattern, location, innerPattern);
restElementWasFound = true;
context.setContainsObjectRestElement(objectPattern, restElementWasFound);
break;
}
const Identifier* propertyName = nullptr;
TreeExpression propertyExpression = 0;
TreeDestructuringPattern innerPattern = 0;
JSTokenLocation location = m_token.m_location;
bool escapedKeyword = match(ESCAPED_KEYWORD);
if (escapedKeyword || matchSpecIdentifier()) {
failIfTrue(match(LET) && (kind == DestructuringKind::DestructureToLet || kind == DestructuringKind::DestructureToConst), "Cannot use 'let' as an identifier name for a LexicalDeclaration");
propertyName = m_token.m_data.ident;
JSToken identifierToken = m_token;
next();
if (consume(COLON))
innerPattern = parseBindingOrAssignmentElement(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth + 1);
else {
semanticFailIfTrue(escapedKeyword, "Cannot use abbreviated destructuring syntax for keyword '", propertyName->impl(), "'");
if (kind == DestructuringKind::DestructureToExpressions) {
bool isEvalOrArguments = m_vm.propertyNames->eval == *propertyName || m_vm.propertyNames->arguments == *propertyName;
if (isEvalOrArguments && strictMode())
reclassifyExpressionError(ErrorIndicatesPattern, ErrorIndicatesNothing);
failIfTrueIfStrict(isEvalOrArguments, "Cannot modify '", propertyName->impl(), "' in strict mode");
}
semanticFailIfTrue(isDisallowedIdentifierAwait(identifierToken), "Cannot use 'await' as a ", destructuringKindToVariableKindName(kind), " ", disallowedIdentifierAwaitReason());
innerPattern = createBindingPattern(context, kind, exportType, *propertyName, identifierToken, bindingContext, duplicateIdentifier);
}
} else {
JSTokenType tokenType = m_token.m_type;
switch (m_token.m_type) {
case DOUBLE:
case INTEGER:
propertyName = &m_parserArena.identifierArena().makeNumericIdentifier(const_cast<VM&>(m_vm), m_token.m_data.doubleValue);
break;
case STRING:
propertyName = m_token.m_data.ident;
wasString = true;
break;
case BIGINT:
propertyName = &m_parserArena.identifierArena().makeBigIntDecimalIdentifier(const_cast<VM&>(m_vm), *m_token.m_data.bigIntString, m_token.m_data.radix);
break;
case OPENBRACKET:
next();
propertyExpression = parseAssignmentExpression(context);
failIfFalse(propertyExpression, "Cannot parse computed property name");
matchOrFail(CLOSEBRACKET, "Expected ']' to end end a computed property name");
break;
default:
if (m_token.m_type != RESERVED && m_token.m_type != RESERVED_IF_STRICT && !(m_token.m_type & KeywordTokenFlag)) {
if (kind == DestructuringKind::DestructureToExpressions)
return 0;
failWithMessage("Expected a property name");
}
propertyName = m_token.m_data.ident;
break;
}
next();
if (!consume(COLON)) {
if (kind == DestructuringKind::DestructureToExpressions)
return 0;
semanticFailIfTrue(tokenType == RESERVED, "Cannot use abbreviated destructuring syntax for reserved name '", propertyName->impl(), "'");
semanticFailIfTrue(tokenType == RESERVED_IF_STRICT, "Cannot use abbreviated destructuring syntax for reserved name '", propertyName->impl(), "' in strict mode");
semanticFailIfTrue(tokenType & KeywordTokenFlag, "Cannot use abbreviated destructuring syntax for keyword '", propertyName->impl(), "'");
failWithMessage("Expected a ':' prior to a named destructuring property");
}
innerPattern = parseBindingOrAssignmentElement(context, kind, exportType, duplicateIdentifier, hasDestructuringPattern, bindingContext, depth + 1);
}
if (kind == DestructuringKind::DestructureToExpressions && !innerPattern)
return 0;
failIfFalse(innerPattern, "Cannot parse this destructuring pattern");
TreeExpression defaultValue = parseDefaultValueForDestructuringPattern(context);
propagateError();
if (propertyExpression) {
context.appendObjectPatternEntry(m_vm, objectPattern, location, propertyExpression, innerPattern, defaultValue);
context.setContainsComputedProperty(objectPattern, true);
} else {
ASSERT(propertyName);
context.appendObjectPatternEntry(objectPattern, location, wasString, *propertyName, innerPattern, defaultValue);
}
} while (consume(COMMA));
if (kind == DestructuringKind::DestructureToExpressions && !match(CLOSEBRACE))
return 0;
consumeOrFail(CLOSEBRACE, restElementWasFound ? "Expected a closing '}' following a rest element destructuring pattern" : "Expected either a closing '}' or an ',' after a property destructuring pattern");
pattern = objectPattern;
break;
}
default: {
if (!matchSpecIdentifier()) {
if (kind == DestructuringKind::DestructureToExpressions)
return 0;
semanticFailureDueToKeyword(destructuringKindToVariableKindName(kind));
if (kind != DestructuringKind::DestructureToParameters)
failIfTrue(match(PRIVATENAME), "Cannot use a private name as a ", destructuringKindToVariableKindName(kind));
failWithMessage("Expected a parameter pattern or a ')' in parameter list");
}
failIfTrue(match(LET) && (kind == DestructuringKind::DestructureToLet || kind == DestructuringKind::DestructureToConst), "Cannot use 'let' as an identifier name for a LexicalDeclaration");
semanticFailIfTrue(isDisallowedIdentifierAwait(m_token), "Cannot use 'await' as a ", destructuringKindToVariableKindName(kind), " ", disallowedIdentifierAwaitReason());
pattern = createBindingPattern(context, kind, exportType, *m_token.m_data.ident, m_token, bindingContext, duplicateIdentifier);
next();
break;
}
}
m_parserState.nonLHSCount = nonLHSCount;
return pattern;
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseDefaultValueForDestructuringPattern(TreeBuilder& context)
{
if (!match(EQUAL))
return 0;
next(TreeBuilder::DontBuildStrings); // consume '='
return parseAssignmentExpression(context);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseForStatement(TreeBuilder& context)
{
ASSERT(match(FOR));
JSTokenLocation location(tokenLocation());
int startLine = tokenLine();
bool isAwaitFor = false;
next();
DepthManager statementDepth(&m_statementDepth);
m_statementDepth++;
if (match(AWAIT)) {
semanticFailIfFalse(currentScope()->isAsyncFunction(), "for-await-of can only be used in an async function or async generator");
isAwaitFor = true;
next();
}
handleProductionOrFail(OPENPAREN, "(", "start", "for-loop header");
int nonLHSCount = m_parserState.nonLHSCount;
int declarations = 0;
JSTokenLocation declLocation(tokenLocation());
JSTextPosition declsStart;
JSTextPosition declsEnd;
TreeExpression decls = 0;
TreeDestructuringPattern pattern = 0;
bool isVarDeclaration = match(VAR);
bool isLetDeclaration = match(LET);
bool isConstDeclaration = match(CONSTTOKEN);
bool forLoopConstDoesNotHaveInitializer = false;
VariableEnvironment dummySet;
VariableEnvironment* lexicalVariables = nullptr;
AutoCleanupLexicalScope lexicalScope;
auto gatherLexicalVariablesIfNecessary = [&] {
if (isLetDeclaration || isConstDeclaration) {
ScopeRef scope = lexicalScope.scope();
lexicalVariables = &scope->finalizeLexicalEnvironment();
} else
lexicalVariables = &dummySet;
};
auto popLexicalScopeIfNecessary = [&] {
if (isLetDeclaration || isConstDeclaration)
popScope(lexicalScope, TreeBuilder::NeedsFreeVariableInfo);
};
if (isVarDeclaration || isLetDeclaration || isConstDeclaration) {
/*
for (var/let/const IDENT in/of expression) statement
for (var/let/const varDeclarationList; expressionOpt; expressionOpt)
*/
if (isLetDeclaration || isConstDeclaration) {
ScopeRef newScope = pushScope();
newScope->setIsLexicalScope();
newScope->preventVarDeclarations();
lexicalScope.setIsValid(newScope, this);
}
TreeDestructuringPattern forInTarget = 0;
TreeExpression forInInitializer = 0;
m_allowsIn = false;
JSTextPosition initStart;
JSTextPosition initEnd;
DeclarationType declarationType;
if (isVarDeclaration)
declarationType = DeclarationType::VarDeclaration;
else if (isLetDeclaration)
declarationType = DeclarationType::LetDeclaration;
else if (isConstDeclaration)
declarationType = DeclarationType::ConstDeclaration;
else
RELEASE_ASSERT_NOT_REACHED();
decls = parseVariableDeclarationList(context, declarations, forInTarget, forInInitializer, declsStart, initStart, initEnd, ForLoopContext, declarationType, ExportType::NotExported, forLoopConstDoesNotHaveInitializer);
m_allowsIn = true;
propagateError();
// Remainder of a standard for loop is handled identically
if (match(SEMICOLON))
goto standardForLoop;
failIfFalse(declarations == 1, "can only declare a single variable in an enumeration");
// Handle for-in with var declaration
JSTextPosition inLocation = tokenStartPosition();
bool isOfEnumeration = false;
if (!match(INTOKEN)) {
failIfFalse(matchContextualKeyword(m_vm.propertyNames->of), "Expected either 'in' or 'of' in enumeration syntax");
isOfEnumeration = true;
next();
} else {
failIfFalse(!isAwaitFor, "Expected 'of' in for-await syntax");
next();
}
bool hasAnyAssignments = !!forInInitializer;
if (hasAnyAssignments) {
if (isOfEnumeration)
internalFailWithMessage(false, "Cannot assign to the loop variable inside a for-of loop header");
if (strictMode() || (isLetDeclaration || isConstDeclaration) || !context.isBindingNode(forInTarget))
internalFailWithMessage(false, "Cannot assign to the loop variable inside a for-in loop header");
}
// While for-in uses Expression, for-of / for-await-of use AssignmentExpression.
// https://tc39.es/ecma262/#sec-for-in-and-for-of-statements
TreeExpression expr = 0;
if (isOfEnumeration)
expr = parseAssignmentExpression(context);
else
expr = parseExpression(context);
failIfFalse(expr, "Expected expression to enumerate");
recordPauseLocation(context.breakpointLocation(expr));
JSTextPosition exprEnd = lastTokenEndPosition();
int endLine = tokenLine();
handleProductionOrFail(CLOSEPAREN, ")", "end", (isOfEnumeration ? "for-of header" : "for-in header"));
const Identifier* unused = nullptr;
startLoop();
TreeStatement statement = parseStatement(context, unused);
endLoop();
failIfFalse(statement, "Expected statement as body of for-", isOfEnumeration ? "of" : "in", " statement");
gatherLexicalVariablesIfNecessary();
TreeStatement result;
if (isOfEnumeration)
result = context.createForOfLoop(isAwaitFor, location, forInTarget, expr, statement, declLocation, declsStart, inLocation, exprEnd, startLine, endLine, *lexicalVariables);
else {
ASSERT(!isAwaitFor);
if (isVarDeclaration && forInInitializer)
result = context.createForInLoop(location, decls, expr, statement, declLocation, declsStart, inLocation, exprEnd, startLine, endLine, *lexicalVariables);
else
result = context.createForInLoop(location, forInTarget, expr, statement, declLocation, declsStart, inLocation, exprEnd, startLine, endLine, *lexicalVariables);
}
popLexicalScopeIfNecessary();
return result;
}
if (!match(SEMICOLON)) {
if (match(OPENBRACE) || match(OPENBRACKET)) {
SavePoint savePoint = createSavePoint(context);
declsStart = tokenStartPosition();
pattern = tryParseDestructuringPatternExpression(context, AssignmentContext::DeclarationStatement);
declsEnd = lastTokenEndPosition();
if (pattern && (match(INTOKEN) || matchContextualKeyword(m_vm.propertyNames->of)))
goto enumerationLoop;
pattern = TreeDestructuringPattern(0);
restoreSavePoint(context, savePoint);
}
m_allowsIn = false;
declsStart = tokenStartPosition();
decls = parseExpression(context);
declsEnd = lastTokenEndPosition();
m_allowsIn = true;
failIfFalse(decls, "Cannot parse for loop declarations");
recordPauseLocation(context.breakpointLocation(decls));
}
if (match(SEMICOLON)) {
standardForLoop:
failIfFalse(!isAwaitFor, "Unexpected a ';' in for-await-of header");
// Standard for loop
if (decls)
recordPauseLocation(context.breakpointLocation(decls));
next();
TreeExpression condition = 0;
failIfTrue(forLoopConstDoesNotHaveInitializer && isConstDeclaration, "const variables in for loops must have initializers");
if (!match(SEMICOLON)) {
condition = parseExpression(context);
failIfFalse(condition, "Cannot parse for loop condition expression");
recordPauseLocation(context.breakpointLocation(condition));
}
consumeOrFail(SEMICOLON, "Expected a ';' after the for loop condition expression");
TreeExpression increment = 0;
if (!match(CLOSEPAREN)) {
increment = parseExpression(context);
failIfFalse(increment, "Cannot parse for loop iteration expression");
recordPauseLocation(context.breakpointLocation(increment));
}
int endLine = tokenLine();
handleProductionOrFail(CLOSEPAREN, ")", "end", "for-loop header");
const Identifier* unused = nullptr;
startLoop();
TreeStatement statement = parseStatement(context, unused);
endLoop();
failIfFalse(statement, "Expected a statement as the body of a for loop");
gatherLexicalVariablesIfNecessary();
TreeStatement result = context.createForLoop(location, decls, condition, increment, statement, startLine, endLine, *lexicalVariables);
popLexicalScopeIfNecessary();
return result;
}
// For-in and For-of loop
enumerationLoop:
failIfFalse(nonLHSCount == m_parserState.nonLHSCount, "Expected a reference on the left hand side of an enumeration statement");
bool isOfEnumeration = false;
if (!match(INTOKEN)) {
failIfFalse(matchContextualKeyword(m_vm.propertyNames->of), "Expected either 'in' or 'of' in enumeration syntax");
isOfEnumeration = true;
next();
} else {
failIfFalse(!isAwaitFor, "Expected 'of' in for-await syntax");
next();
}
// While for-in uses Expression, for-of / for-await-of use AssignmentExpression.
// https://tc39.es/ecma262/#sec-for-in-and-for-of-statements
TreeExpression expr = 0;
if (isOfEnumeration)
expr = parseAssignmentExpression(context);
else
expr = parseExpression(context);
failIfFalse(expr, "Cannot parse subject for-", isOfEnumeration ? "of" : "in", " statement");
recordPauseLocation(context.breakpointLocation(expr));
JSTextPosition exprEnd = lastTokenEndPosition();
int endLine = tokenLine();
handleProductionOrFail(CLOSEPAREN, ")", "end", (isOfEnumeration ? "for-of header" : "for-in header"));
const Identifier* unused = nullptr;
startLoop();
TreeStatement statement = parseStatement(context, unused);
endLoop();
failIfFalse(statement, "Expected a statement as the body of a for-", isOfEnumeration ? "of" : "in", "loop");
gatherLexicalVariablesIfNecessary();
TreeStatement result;
if (pattern) {
ASSERT(!decls);
if (isOfEnumeration)
result = context.createForOfLoop(isAwaitFor, location, pattern, expr, statement, declLocation, declsStart, declsEnd, exprEnd, startLine, endLine, *lexicalVariables);
else {
ASSERT(!isAwaitFor);
result = context.createForInLoop(location, pattern, expr, statement, declLocation, declsStart, declsEnd, exprEnd, startLine, endLine, *lexicalVariables);
}
popLexicalScopeIfNecessary();
return result;
}
semanticFailIfFalse(isSimpleAssignmentTarget(context, decls), "Left side of assignment is not a reference");
if (isOfEnumeration)
result = context.createForOfLoop(isAwaitFor, location, decls, expr, statement, declLocation, declsStart, declsEnd, exprEnd, startLine, endLine, *lexicalVariables);
else {
ASSERT(!isAwaitFor);
result = context.createForInLoop(location, decls, expr, statement, declLocation, declsStart, declsEnd, exprEnd, startLine, endLine, *lexicalVariables);
}
popLexicalScopeIfNecessary();
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseBreakStatement(TreeBuilder& context)
{
ASSERT(match(BREAK));
JSTokenLocation location(tokenLocation());
JSTextPosition start = tokenStartPosition();
JSTextPosition end = tokenEndPosition();
next();
if (autoSemiColon()) {
semanticFailIfFalse(breakIsValid(), "'break' is only valid inside a switch or loop statement");
return context.createBreakStatement(location, &m_vm.propertyNames->nullIdentifier, start, end);
}
failIfFalse(matchSpecIdentifier(), "Expected an identifier as the target for a break statement");
const Identifier* ident = m_token.m_data.ident;
semanticFailIfFalse(getLabel(ident), "Cannot use the undeclared label '", ident->impl(), "'");
end = tokenEndPosition();
next();
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted break statement");
return context.createBreakStatement(location, ident, start, end);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseContinueStatement(TreeBuilder& context)
{
ASSERT(match(CONTINUE));
JSTokenLocation location(tokenLocation());
JSTextPosition start = tokenStartPosition();
JSTextPosition end = tokenEndPosition();
next();
if (autoSemiColon()) {
semanticFailIfFalse(continueIsValid(), "'continue' is only valid inside a loop statement");
return context.createContinueStatement(location, &m_vm.propertyNames->nullIdentifier, start, end);
}
failIfFalse(matchSpecIdentifier(), "Expected an identifier as the target for a continue statement");
const Identifier* ident = m_token.m_data.ident;
ScopeLabelInfo* label = getLabel(ident);
semanticFailIfFalse(label, "Cannot use the undeclared label '", ident->impl(), "'");
semanticFailIfFalse(label->isLoop, "Cannot continue to the label '", ident->impl(), "' as it is not targeting a loop");
end = tokenEndPosition();
next();
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted continue statement");
return context.createContinueStatement(location, ident, start, end);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseReturnStatement(TreeBuilder& context)
{
ASSERT(match(RETURN));
JSTokenLocation location(tokenLocation());
semanticFailIfFalse(currentScope()->isFunction(), "Return statements are only valid inside functions");
JSTextPosition start = tokenStartPosition();
JSTextPosition end = tokenEndPosition();
next();
// We do the auto semicolon check before attempting to parse expression
// as we need to ensure the a line break after the return correctly terminates
// the statement
if (match(SEMICOLON))
end = tokenEndPosition();
if (autoSemiColon())
return context.createReturnStatement(location, 0, start, end);
TreeExpression expr = parseExpression(context, IsOnlyChildOfStatement::Yes);
failIfFalse(expr, "Cannot parse the return expression");
end = lastTokenEndPosition();
if (match(SEMICOLON))
end = tokenEndPosition();
if (!autoSemiColon())
failWithMessage("Expected a ';' following a return statement");
return context.createReturnStatement(location, expr, start, end);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseThrowStatement(TreeBuilder& context)
{
ASSERT(match(THROW));
JSTokenLocation location(tokenLocation());
JSTextPosition start = tokenStartPosition();
next();
failIfTrue(match(SEMICOLON), "Expected expression after 'throw'");
semanticFailIfTrue(autoSemiColon(), "Cannot have a newline after 'throw'");
TreeExpression expr = parseExpression(context, IsOnlyChildOfStatement::Yes);
failIfFalse(expr, "Cannot parse expression for throw statement");
JSTextPosition end = lastTokenEndPosition();
failIfFalse(autoSemiColon(), "Expected a ';' after a throw statement");
return context.createThrowStatement(location, expr, start, end);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseWithStatement(TreeBuilder& context)
{
ASSERT(match(WITH));
JSTokenLocation location(tokenLocation());
semanticFailIfTrue(strictMode(), "'with' statements are not valid in strict mode");
currentScope()->setNeedsFullActivation();
int startLine = tokenLine();
next();
handleProductionOrFail(OPENPAREN, "(", "start", "subject of a 'with' statement");
int start = tokenStart();
TreeExpression expr = parseExpression(context);
failIfFalse(expr, "Cannot parse 'with' subject expression");
recordPauseLocation(context.breakpointLocation(expr));
JSTextPosition end = lastTokenEndPosition();
int endLine = tokenLine();
handleProductionOrFail(CLOSEPAREN, ")", "start", "subject of a 'with' statement");
const Identifier* unused = nullptr;
TreeStatement statement = parseStatement(context, unused);
failIfFalse(statement, "A 'with' statement must have a body");
return context.createWithStatement(location, expr, statement, start, end, startLine, endLine);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseSwitchStatement(TreeBuilder& context)
{
ASSERT(match(SWITCH));
JSTokenLocation location(tokenLocation());
int startLine = tokenLine();
next();
handleProductionOrFail(OPENPAREN, "(", "start", "subject of a 'switch'");
TreeExpression expr = parseExpression(context);
failIfFalse(expr, "Cannot parse switch subject expression");
recordPauseLocation(context.breakpointLocation(expr));
int endLine = tokenLine();
handleProductionOrFail(CLOSEPAREN, ")", "end", "subject of a 'switch'");
handleProductionOrFail(OPENBRACE, "{", "start", "body of a 'switch'");
AutoPopScopeRef lexicalScope(this, pushScope());
lexicalScope->setIsLexicalScope();
lexicalScope->preventVarDeclarations();
startSwitch();
TreeClauseList firstClauses = parseSwitchClauses(context);
propagateError();
TreeClause defaultClause = parseSwitchDefaultClause(context);
propagateError();
TreeClauseList secondClauses = parseSwitchClauses(context);
propagateError();
endSwitch();
handleProductionOrFail(CLOSEBRACE, "}", "end", "body of a 'switch'");
TreeStatement result = context.createSwitchStatement(location, expr, firstClauses, defaultClause, secondClauses, startLine, endLine, lexicalScope->finalizeLexicalEnvironment(), lexicalScope->takeFunctionDeclarations());
popScope(lexicalScope, TreeBuilder::NeedsFreeVariableInfo);
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeClauseList Parser<LexerType>::parseSwitchClauses(TreeBuilder& context)
{
if (!match(CASE))
return 0;
unsigned startOffset = tokenStart();
next();
TreeExpression condition = parseExpression(context);
failIfFalse(condition, "Cannot parse switch clause");
consumeOrFail(COLON, "Expected a ':' after switch clause expression");
TreeSourceElements statements = parseSourceElements(context, DontCheckForStrictMode);
failIfFalse(statements, "Cannot parse the body of a switch clause");
TreeClause clause = context.createClause(condition, statements);
context.setStartOffset(clause, startOffset);
TreeClauseList clauseList = context.createClauseList(clause);
TreeClauseList tail = clauseList;
while (match(CASE)) {
startOffset = tokenStart();
next();
TreeExpression condition = parseExpression(context);
failIfFalse(condition, "Cannot parse switch case expression");
consumeOrFail(COLON, "Expected a ':' after switch clause expression");
TreeSourceElements statements = parseSourceElements(context, DontCheckForStrictMode);
failIfFalse(statements, "Cannot parse the body of a switch clause");
clause = context.createClause(condition, statements);
context.setStartOffset(clause, startOffset);
tail = context.createClauseList(tail, clause);
}
return clauseList;
}
template <typename LexerType>
template <class TreeBuilder> TreeClause Parser<LexerType>::parseSwitchDefaultClause(TreeBuilder& context)
{
if (!match(DEFAULT))
return 0;
unsigned startOffset = tokenStart();
next();
consumeOrFail(COLON, "Expected a ':' after switch default clause");
TreeSourceElements statements = parseSourceElements(context, DontCheckForStrictMode);
failIfFalse(statements, "Cannot parse the body of a switch default clause");
TreeClause result = context.createClause(0, statements);
context.setStartOffset(result, startOffset);
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseTryStatement(TreeBuilder& context)
{
ASSERT(match(TRY));
JSTokenLocation location(tokenLocation());
TreeStatement tryBlock = 0;
TreeDestructuringPattern catchPattern = 0;
TreeStatement catchBlock = 0;
TreeStatement finallyBlock = 0;
int firstLine = tokenLine();
next();
matchOrFail(OPENBRACE, "Expected a block statement as body of a try statement");
tryBlock = parseBlockStatement(context);
failIfFalse(tryBlock, "Cannot parse the body of try block");
int lastLine = m_lastTokenEndPosition.line;
VariableEnvironment catchEnvironment;
if (match(CATCH)) {
next();
if (match(OPENBRACE)) {
catchBlock = parseBlockStatement(context);
failIfFalse(catchBlock, "Unable to parse 'catch' block");
} else {
handleProductionOrFail(OPENPAREN, "(", "start", "'catch' target");
DepthManager statementDepth(&m_statementDepth);
m_statementDepth++;
AutoPopScopeRef catchScope(this, pushScope());
catchScope->setIsLexicalScope();
catchScope->preventVarDeclarations();
const Identifier* ident = nullptr;
if (matchSpecIdentifier()) {
catchScope->setIsSimpleCatchParameterScope();
ident = m_token.m_data.ident;
catchPattern = context.createBindingLocation(m_token.m_location, *ident, m_token.m_startPosition, m_token.m_endPosition, AssignmentContext::DeclarationStatement);
next();
failIfTrueIfStrict(catchScope->declareLexicalVariable(ident, false) & DeclarationResult::InvalidStrictMode, "Cannot declare a catch variable named '", ident->impl(), "' in strict mode");
} else {
catchPattern = parseDestructuringPattern(context, DestructuringKind::DestructureToCatchParameters, ExportType::NotExported);
failIfFalse(catchPattern, "Cannot parse this destructuring pattern");
}
handleProductionOrFail(CLOSEPAREN, ")", "end", "'catch' target");
matchOrFail(OPENBRACE, "Expected exception handler to be a block statement");
constexpr bool isCatchBlock = true;
catchBlock = parseBlockStatement(context, isCatchBlock);
failIfFalse(catchBlock, "Unable to parse 'catch' block");
catchEnvironment = catchScope->finalizeLexicalEnvironment();
RELEASE_ASSERT(!ident || (catchEnvironment.size() == 1 && catchEnvironment.contains(ident->impl())));
popScope(catchScope, TreeBuilder::NeedsFreeVariableInfo);
}
}
if (match(FINALLY)) {
next();
matchOrFail(OPENBRACE, "Expected block statement for finally body");
finallyBlock = parseBlockStatement(context);
failIfFalse(finallyBlock, "Cannot parse finally body");
}
failIfFalse(catchBlock || finallyBlock, "Try statements must have at least a catch or finally block");
return context.createTryStatement(location, tryBlock, catchPattern, catchBlock, finallyBlock, firstLine, lastLine, catchEnvironment);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseDebuggerStatement(TreeBuilder& context)
{
ASSERT(match(DEBUGGER));
JSTokenLocation location(tokenLocation());
int startLine = tokenLine();
int endLine = startLine;
next();
if (match(SEMICOLON))
startLine = tokenLine();
failIfFalse(autoSemiColon(), "Debugger keyword must be followed by a ';'");
return context.createDebugger(location, startLine, endLine);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseBlockStatement(TreeBuilder& context, bool isCatchBlock)
{
ASSERT(match(OPENBRACE));
// We should treat the first block statement of the function (the body of the function) as the lexical
// scope of the function itself, and not the lexical scope of a 'block' statement within the function.
AutoCleanupLexicalScope lexicalScope;
bool shouldPushLexicalScope = m_statementDepth > 0;
if (shouldPushLexicalScope) {
ScopeRef newScope = pushScope();
newScope->setIsLexicalScope();
newScope->preventVarDeclarations();
if (isCatchBlock)
newScope->setIsCatchBlockScope();
lexicalScope.setIsValid(newScope, this);
}
JSTokenLocation location(tokenLocation());
int startOffset = m_token.m_data.offset;
int start = tokenLine();
VariableEnvironment emptyEnvironment;
DeclarationStacks::FunctionStack emptyFunctionStack;
next();
if (match(CLOSEBRACE)) {
int endOffset = m_token.m_data.offset;
next();
TreeStatement result = context.createBlockStatement(location, 0, start, m_lastTokenEndPosition.line, shouldPushLexicalScope ? currentScope()->finalizeLexicalEnvironment() : emptyEnvironment, shouldPushLexicalScope ? currentScope()->takeFunctionDeclarations() : WTFMove(emptyFunctionStack));
context.setStartOffset(result, startOffset);
context.setEndOffset(result, endOffset);
if (shouldPushLexicalScope)
popScope(lexicalScope, TreeBuilder::NeedsFreeVariableInfo);
return result;
}
TreeSourceElements subtree = parseSourceElements(context, DontCheckForStrictMode);
failIfFalse(subtree, "Cannot parse the body of the block statement");
matchOrFail(CLOSEBRACE, "Expected a closing '}' at the end of a block statement");
int endOffset = m_token.m_data.offset;
next();
TreeStatement result = context.createBlockStatement(location, subtree, start, m_lastTokenEndPosition.line, shouldPushLexicalScope ? currentScope()->finalizeLexicalEnvironment() : emptyEnvironment, shouldPushLexicalScope ? currentScope()->takeFunctionDeclarations() : WTFMove(emptyFunctionStack));
context.setStartOffset(result, startOffset);
context.setEndOffset(result, endOffset);
if (shouldPushLexicalScope)
popScope(lexicalScope, TreeBuilder::NeedsFreeVariableInfo);
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseStatement(TreeBuilder& context, const Identifier*& directive, unsigned* directiveLiteralLength)
{
DepthManager statementDepth(&m_statementDepth);
m_statementDepth++;
int nonTrivialExpressionCount = 0;
failIfStackOverflow();
TreeStatement result = 0;
bool shouldSetEndOffset = true;
bool shouldSetPauseLocation = false;
bool parentAllowsFunctionDeclarationAsStatement = m_immediateParentAllowsFunctionDeclarationInStatement;
m_immediateParentAllowsFunctionDeclarationInStatement = false;
switch (m_token.m_type) {
case OPENBRACE:
result = parseBlockStatement(context);
shouldSetEndOffset = false;
break;
case VAR:
result = parseVariableDeclaration(context, DeclarationType::VarDeclaration);
shouldSetPauseLocation = true;
break;
case FUNCTION: {
result = parseFunctionDeclarationStatement(context, parentAllowsFunctionDeclarationAsStatement);
break;
}
case SEMICOLON: {
JSTokenLocation location(tokenLocation());
next();
result = context.createEmptyStatement(location);
shouldSetPauseLocation = true;
break;
}
case IF:
result = parseIfStatement(context);
break;
case DO:
result = parseDoWhileStatement(context);
break;
case WHILE:
result = parseWhileStatement(context);
break;
case FOR:
result = parseForStatement(context);
break;
case CONTINUE:
result = parseContinueStatement(context);
shouldSetPauseLocation = true;
break;
case BREAK:
result = parseBreakStatement(context);
shouldSetPauseLocation = true;
break;
case RETURN:
result = parseReturnStatement(context);
shouldSetPauseLocation = true;
break;
case WITH:
result = parseWithStatement(context);
break;
case SWITCH:
result = parseSwitchStatement(context);
break;
case THROW:
result = parseThrowStatement(context);
shouldSetPauseLocation = true;
break;
case TRY:
result = parseTryStatement(context);
break;
case DEBUGGER:
result = parseDebuggerStatement(context);
shouldSetPauseLocation = true;
break;
case EOFTOK:
case CASE:
case CLOSEBRACE:
case DEFAULT:
// These tokens imply the end of a set of source elements
return 0;
case LET: {
// https://tc39.es/ecma262/#sec-expression-statement
// ExpressionStatement's lookahead includes `let [` sequence.
SavePoint savePoint = createSavePoint(context);
next();
failIfTrue(match(OPENBRACKET), "Cannot use lexical declaration in single-statement context");
restoreSavePoint(context, savePoint);
if (!strictMode())
goto identcase;
goto defaultCase;
}
case IDENT:
if (UNLIKELY(*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped)) {
SavePoint savePoint = createSavePoint(context);
next();
failIfTrue(match(FUNCTION) && !m_lexer->hasLineTerminatorBeforeToken(), "Cannot use async function declaration in single-statement context");
restoreSavePoint(context, savePoint);
}
FALLTHROUGH;
case AWAIT:
case YIELD: {
identcase:
bool allowFunctionDeclarationAsStatement = false;
result = parseExpressionOrLabelStatement(context, allowFunctionDeclarationAsStatement);
shouldSetPauseLocation = !context.shouldSkipPauseLocation(result);
break;
}
case STRING:
directive = m_token.m_data.ident;
if (directiveLiteralLength)
*directiveLiteralLength = m_token.m_location.endOffset - m_token.m_location.startOffset;
nonTrivialExpressionCount = m_parserState.nonTrivialExpressionCount;
FALLTHROUGH;
default:
defaultCase:
TreeStatement exprStatement = parseExpressionStatement(context);
if (directive && nonTrivialExpressionCount != m_parserState.nonTrivialExpressionCount)
directive = nullptr;
result = exprStatement;
shouldSetPauseLocation = true;
break;
}
if (result) {
if (shouldSetEndOffset)
context.setEndOffset(result, m_lastTokenEndPosition.offset);
if (shouldSetPauseLocation)
recordPauseLocation(context.breakpointLocation(result));
}
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseFunctionDeclarationStatement(TreeBuilder& context, bool parentAllowsFunctionDeclarationAsStatement)
{
semanticFailIfTrue(strictMode(), "Function declarations are only allowed inside blocks or switch statements in strict mode");
failIfFalse(parentAllowsFunctionDeclarationAsStatement, "Function declarations are only allowed inside block statements or at the top level of a program");
if (!currentScope()->isFunction() && !closestParentOrdinaryFunctionNonLexicalScope()->isEvalContext()) {
// We only implement annex B.3.3 if we're in function mode or eval mode. Otherwise, we fall back
// to hoisting behavior.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=155813
DepthManager statementDepth(&m_statementDepth);
m_statementDepth = 1;
return parseFunctionDeclaration(context, FunctionDeclarationType::Statement);
}
// Any function declaration that isn't in a block is a syntax error unless it's
// in an if/else statement. If it's in an if/else statement, we will magically
// treat it as if the if/else statement is inside a block statement.
// to the very top like a "var". For example:
// function a() {
// if (cond) function foo() { }
// }
// will be rewritten as:
// function a() {
// if (cond) { function foo() { } }
// }
AutoPopScopeRef blockScope(this, pushScope());
blockScope->setIsLexicalScope();
blockScope->preventVarDeclarations();
JSTokenLocation location(tokenLocation());
int start = tokenLine();
TreeStatement function = parseFunctionDeclaration(context, FunctionDeclarationType::Statement);
propagateError();
failIfFalse(function, "Expected valid function statement after 'function' keyword");
TreeSourceElements sourceElements = context.createSourceElements();
context.appendStatement(sourceElements, function);
TreeStatement result = context.createBlockStatement(location, sourceElements, start, m_lastTokenEndPosition.line, currentScope()->finalizeLexicalEnvironment(), currentScope()->takeFunctionDeclarations());
popScope(blockScope, TreeBuilder::NeedsFreeVariableInfo);
return result;
}
template <typename LexerType>
template <class TreeBuilder> bool Parser<LexerType>::parseFormalParameters(TreeBuilder& context, TreeFormalParameterList list, bool isArrowFunction, bool isMethod, unsigned& parameterCount)
{
#define failIfDuplicateIfViolation() \
if (duplicateParameter) {\
semanticFailIfTrue(hasDefaultParameterValues, "Duplicate parameter '", duplicateParameter->impl(), "' not allowed in function with default parameter values");\
semanticFailIfTrue(hasDestructuringPattern, "Duplicate parameter '", duplicateParameter->impl(), "' not allowed in function with destructuring parameters");\
semanticFailIfTrue(isRestParameter, "Duplicate parameter '", duplicateParameter->impl(), "' not allowed in function with a rest parameter");\
semanticFailIfTrue(isArrowFunction, "Duplicate parameter '", duplicateParameter->impl(), "' not allowed in an arrow function");\
semanticFailIfTrue(isMethod, "Duplicate parameter '", duplicateParameter->impl(), "' not allowed in a method");\
}
bool hasDefaultParameterValues = false;
bool hasDestructuringPattern = false;
bool isRestParameter = false;
const Identifier* duplicateParameter = nullptr;
unsigned restParameterStart = 0;
do {
TreeDestructuringPattern parameter = 0;
TreeExpression defaultValue = 0;
if (UNLIKELY(match(CLOSEPAREN)))
break;
if (match(DOTDOTDOT)) {
next();
semanticFailIfTrue(!m_parserState.allowAwait && match(AWAIT), "Cannot use 'await' as a parameter name in an async function");
TreeDestructuringPattern destructuringPattern = parseDestructuringPattern(context, DestructuringKind::DestructureToParameters, ExportType::NotExported, &duplicateParameter, &hasDestructuringPattern);
propagateError();
parameter = context.createRestParameter(destructuringPattern, restParameterStart);
failIfTrue(match(COMMA), "Rest parameter should be the last parameter in a function declaration"); // Let's have a good error message for this common case.
isRestParameter = true;
} else
parameter = parseDestructuringPattern(context, DestructuringKind::DestructureToParameters, ExportType::NotExported, &duplicateParameter, &hasDestructuringPattern);
failIfFalse(parameter, "Cannot parse parameter pattern");
if (!isRestParameter) {
defaultValue = parseDefaultValueForDestructuringPattern(context);
if (defaultValue)
hasDefaultParameterValues = true;
}
propagateError();
failIfDuplicateIfViolation();
if (isRestParameter || defaultValue || hasDestructuringPattern)
currentScope()->setHasNonSimpleParameterList();
context.appendParameter(list, parameter, defaultValue);
if (!isRestParameter) {
restParameterStart++;
if (!hasDefaultParameterValues)
parameterCount++;
}
} while (!isRestParameter && consume(COMMA));
return true;
#undef failIfDuplicateIfViolation
}
template <typename LexerType>
template <class TreeBuilder> TreeFunctionBody Parser<LexerType>::parseFunctionBody(
TreeBuilder& context, SyntaxChecker& syntaxChecker, const JSTokenLocation& startLocation, int startColumn, int functionKeywordStart, int functionNameStart, int parametersStart,
ConstructorKind constructorKind, SuperBinding superBinding, FunctionBodyType bodyType, unsigned parameterCount, SourceParseMode parseMode)
{
SetForScope<bool> overrideParsingClassFieldInitializer(m_parserState.isParsingClassFieldInitializer, bodyType == StandardFunctionBodyBlock ? false : m_parserState.isParsingClassFieldInitializer);
bool isArrowFunctionBodyExpression = bodyType == ArrowFunctionBodyExpression;
if (!isArrowFunctionBodyExpression) {
next();
if (match(CLOSEBRACE)) {
unsigned endColumn = tokenColumn();
SuperBinding functionSuperBinding = adjustSuperBindingForBaseConstructor(constructorKind, superBinding, currentScope());
return context.createFunctionMetadata(startLocation, tokenLocation(), startColumn, endColumn, functionKeywordStart, functionNameStart, parametersStart, strictMode(), constructorKind, functionSuperBinding, parameterCount, parseMode, isArrowFunctionBodyExpression);
}
}
DepthManager statementDepth(&m_statementDepth);
m_statementDepth = 0;
if (bodyType == ArrowFunctionBodyExpression) {
if (m_debuggerParseData)
failIfFalse(parseArrowFunctionSingleExpressionBodySourceElements(context), "Cannot parse body of this arrow function");
else
failIfFalse(parseArrowFunctionSingleExpressionBodySourceElements(syntaxChecker), "Cannot parse body of this arrow function");
} else {
if (m_debuggerParseData)
failIfFalse(parseSourceElements(context, CheckForStrictMode), bodyType == StandardFunctionBodyBlock ? "Cannot parse body of this function" : "Cannot parse body of this arrow function");
else
failIfFalse(parseSourceElements(syntaxChecker, CheckForStrictMode), bodyType == StandardFunctionBodyBlock ? "Cannot parse body of this function" : "Cannot parse body of this arrow function");
}
unsigned endColumn = tokenColumn();
SuperBinding functionSuperBinding = adjustSuperBindingForBaseConstructor(constructorKind, superBinding, currentScope());
return context.createFunctionMetadata(startLocation, tokenLocation(), startColumn, endColumn, functionKeywordStart, functionNameStart, parametersStart, strictMode(), constructorKind, functionSuperBinding, parameterCount, parseMode, isArrowFunctionBodyExpression);
}
static const char* stringArticleForFunctionMode(SourceParseMode mode)
{
switch (mode) {
case SourceParseMode::GetterMode:
case SourceParseMode::SetterMode:
case SourceParseMode::NormalFunctionMode:
case SourceParseMode::MethodMode:
case SourceParseMode::GeneratorBodyMode:
case SourceParseMode::GeneratorWrapperFunctionMode:
case SourceParseMode::GeneratorWrapperMethodMode:
return "a ";
case SourceParseMode::ArrowFunctionMode:
case SourceParseMode::AsyncFunctionMode:
case SourceParseMode::AsyncFunctionBodyMode:
case SourceParseMode::AsyncMethodMode:
case SourceParseMode::AsyncArrowFunctionBodyMode:
case SourceParseMode::AsyncArrowFunctionMode:
case SourceParseMode::AsyncGeneratorWrapperFunctionMode:
case SourceParseMode::AsyncGeneratorBodyMode:
case SourceParseMode::AsyncGeneratorWrapperMethodMode:
return "an ";
case SourceParseMode::ProgramMode:
case SourceParseMode::ModuleAnalyzeMode:
case SourceParseMode::ModuleEvaluateMode:
case SourceParseMode::ClassFieldInitializerMode:
RELEASE_ASSERT_NOT_REACHED();
return "";
}
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
static const char* stringForFunctionMode(SourceParseMode mode)
{
switch (mode) {
case SourceParseMode::GetterMode:
return "getter";
case SourceParseMode::SetterMode:
return "setter";
case SourceParseMode::NormalFunctionMode:
return "function";
case SourceParseMode::MethodMode:
return "method";
case SourceParseMode::GeneratorBodyMode:
return "generator";
case SourceParseMode::GeneratorWrapperFunctionMode:
case SourceParseMode::GeneratorWrapperMethodMode:
return "generator function";
case SourceParseMode::ArrowFunctionMode:
return "arrow function";
case SourceParseMode::AsyncFunctionMode:
case SourceParseMode::AsyncFunctionBodyMode:
return "async function";
case SourceParseMode::AsyncMethodMode:
return "async method";
case SourceParseMode::AsyncArrowFunctionBodyMode:
case SourceParseMode::AsyncArrowFunctionMode:
return "async arrow function";
case SourceParseMode::AsyncGeneratorWrapperFunctionMode:
case SourceParseMode::AsyncGeneratorBodyMode:
return "async generator function";
case SourceParseMode::AsyncGeneratorWrapperMethodMode:
return "async generator method";
case SourceParseMode::ProgramMode:
case SourceParseMode::ModuleAnalyzeMode:
case SourceParseMode::ModuleEvaluateMode:
case SourceParseMode::ClassFieldInitializerMode:
RELEASE_ASSERT_NOT_REACHED();
return "";
}
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
template <typename LexerType> template <class TreeBuilder, class FunctionInfoType> typename TreeBuilder::FormalParameterList Parser<LexerType>::parseFunctionParameters(TreeBuilder& context, SourceParseMode mode, FunctionInfoType& functionInfo)
{
RELEASE_ASSERT(!(SourceParseModeSet(SourceParseMode::ProgramMode, SourceParseMode::ModuleAnalyzeMode, SourceParseMode::ModuleEvaluateMode).contains(mode)));
TreeFormalParameterList parameterList = context.createFormalParameterList();
SetForScope<FunctionParsePhase> functionParsePhasePoisoner(m_parserState.functionParsePhase, FunctionParsePhase::Parameters);
if (UNLIKELY((SourceParseModeSet(SourceParseMode::ArrowFunctionMode, SourceParseMode::AsyncArrowFunctionMode).contains(mode)))) {
if (!matchSpecIdentifier() && !match(OPENPAREN)) {
semanticFailureDueToKeyword(stringForFunctionMode(mode), " name");
failWithMessage("Expected an arrow function input parameter");
} else {
if (match(OPENPAREN)) {
next();
if (match(CLOSEPAREN)) {
functionInfo.parameterCount = 0;
} else {
bool isArrowFunction = true;
bool isMethod = false;
failIfFalse(parseFormalParameters(context, parameterList, isArrowFunction, isMethod, functionInfo.parameterCount), "Cannot parse parameters for this ", stringForFunctionMode(mode));
}
consumeOrFail(CLOSEPAREN, "Expected a ')' or a ',' after a parameter declaration");
} else {
functionInfo.parameterCount = 1;
auto parameter = parseDestructuringPattern(context, DestructuringKind::DestructureToParameters, ExportType::NotExported);
failIfFalse(parameter, "Cannot parse parameter pattern");
context.appendParameter(parameterList, parameter, 0);
}
}
return parameterList;
}
if (!consume(OPENPAREN)) {
semanticFailureDueToKeyword(stringForFunctionMode(mode), " name");
failWithMessage("Expected an opening '(' before a ", stringForFunctionMode(mode), "'s parameter list");
}
if (mode == SourceParseMode::GetterMode) {
consumeOrFail(CLOSEPAREN, "getter functions must have no parameters");
functionInfo.parameterCount = 0;
} else if (mode == SourceParseMode::SetterMode) {
failIfTrue(match(CLOSEPAREN), "setter functions must have one parameter");
const Identifier* duplicateParameter = nullptr;
bool hasDestructuringPattern = false;
auto parameter = parseDestructuringPattern(context, DestructuringKind::DestructureToParameters, ExportType::NotExported, &duplicateParameter, &hasDestructuringPattern);
failIfFalse(parameter, "setter functions must have one parameter");
auto defaultValue = parseDefaultValueForDestructuringPattern(context);
propagateError();
if (defaultValue || hasDestructuringPattern) {
semanticFailIfTrue(duplicateParameter, "Duplicate parameter '", duplicateParameter->impl(), "' not allowed in function with non-simple parameter list");
currentScope()->setHasNonSimpleParameterList();
}
context.appendParameter(parameterList, parameter, defaultValue);
functionInfo.parameterCount = defaultValue ? 0 : 1;
failIfTrue(match(COMMA), "setter functions must have one parameter");
consumeOrFail(CLOSEPAREN, "Expected a ')' after a parameter declaration");
} else {
if (match(CLOSEPAREN)) {
functionInfo.parameterCount = 0;
} else {
bool isArrowFunction = false;
bool isMethod = isMethodParseMode(mode);
failIfFalse(parseFormalParameters(context, parameterList, isArrowFunction, isMethod, functionInfo.parameterCount), "Cannot parse parameters for this ", stringForFunctionMode(mode));
}
consumeOrFail(CLOSEPAREN, "Expected a ')' or a ',' after a parameter declaration");
}
return parameterList;
}
template <typename LexerType>
template <class TreeBuilder> typename TreeBuilder::FormalParameterList Parser<LexerType>::createGeneratorParameters(TreeBuilder& context, unsigned& parameterCount)
{
auto parameters = context.createFormalParameterList();
JSTokenLocation location(tokenLocation());
JSTextPosition position = tokenStartPosition();
auto addParameter = [&](const Identifier& name) {
declareParameter(&name);
auto binding = context.createBindingLocation(location, name, position, position, AssignmentContext::DeclarationStatement);
context.appendParameter(parameters, binding, 0);
++parameterCount;
};
// @generator
addParameter(m_vm.propertyNames->generatorPrivateName);
// @generatorState
addParameter(m_vm.propertyNames->generatorStatePrivateName);
// @generatorValue
addParameter(m_vm.propertyNames->generatorValuePrivateName);
// @generatorResumeMode
addParameter(m_vm.propertyNames->generatorResumeModePrivateName);
// @generatorFrame
addParameter(m_vm.propertyNames->generatorFramePrivateName);
return parameters;
}
template <typename LexerType>
template <class TreeBuilder> bool Parser<LexerType>::parseFunctionInfo(TreeBuilder& context, FunctionNameRequirements requirements, SourceParseMode mode, bool nameIsInContainingScope, ConstructorKind constructorKind, SuperBinding expectedSuperBinding, int functionKeywordStart, ParserFunctionInfo<TreeBuilder>& functionInfo, FunctionDefinitionType functionDefinitionType, Optional<int> functionConstructorParametersEndPosition)
{
RELEASE_ASSERT(isFunctionParseMode(mode));
ScopeRef parentScope = currentScope();
bool isDisallowedAwaitFunctionName = isDisallowedIdentifierAwait(m_token);
const char* isDisallowedAwaitFunctionNameReason = isDisallowedAwaitFunctionName ? disallowedIdentifierAwaitReason() : nullptr;
AutoPopScopeRef functionScope(this, pushScope());
functionScope->setSourceParseMode(mode);
functionScope->setExpectedSuperBinding(expectedSuperBinding);
functionScope->setConstructorKind(constructorKind);
SetForScope<FunctionParsePhase> functionParsePhasePoisoner(m_parserState.functionParsePhase, FunctionParsePhase::Body);
int functionNameStart = m_token.m_location.startOffset;
const Identifier* lastFunctionName = m_parserState.lastFunctionName;
m_parserState.lastFunctionName = nullptr;
int parametersStart = -1;
JSTokenLocation startLocation;
int startColumn = -1;
FunctionBodyType functionBodyType;
auto loadCachedFunction = [&] () -> bool {
if (UNLIKELY(!Options::useSourceProviderCache()))
return false;
if (UNLIKELY(m_debuggerParseData))
return false;
ASSERT(parametersStart != -1);
ASSERT(startColumn != -1);
// If we know about this function already, we can use the cached info and skip the parser to the end of the function.
if (const SourceProviderCacheItem* cachedInfo = TreeBuilder::CanUseFunctionCache ? findCachedFunctionInfo(parametersStart) : nullptr) {
// If we're in a strict context, the cached function info must say it was strict too.
ASSERT(!strictMode() || cachedInfo->strictMode);
JSTokenLocation endLocation;
ConstructorKind constructorKind = static_cast<ConstructorKind>(cachedInfo->constructorKind);
SuperBinding expectedSuperBinding = static_cast<SuperBinding>(cachedInfo->expectedSuperBinding);
endLocation.line = cachedInfo->lastTokenLine;
endLocation.startOffset = cachedInfo->lastTokenStartOffset;
endLocation.lineStartOffset = cachedInfo->lastTokenLineStartOffset;
ASSERT(endLocation.startOffset >= endLocation.lineStartOffset);
bool endColumnIsOnStartLine = endLocation.line == functionInfo.startLine;
unsigned currentLineStartOffset = m_lexer->currentLineStartOffset();
unsigned bodyEndColumn = endColumnIsOnStartLine ? endLocation.startOffset - currentLineStartOffset : endLocation.startOffset - endLocation.lineStartOffset;
ASSERT(endLocation.startOffset >= endLocation.lineStartOffset);
FunctionBodyType functionBodyType;
if (UNLIKELY(SourceParseModeSet(SourceParseMode::ArrowFunctionMode, SourceParseMode::AsyncArrowFunctionMode).contains(mode)))
functionBodyType = cachedInfo->isBodyArrowExpression ? ArrowFunctionBodyExpression : ArrowFunctionBodyBlock;
else
functionBodyType = StandardFunctionBodyBlock;
SuperBinding functionSuperBinding = adjustSuperBindingForBaseConstructor(constructorKind, expectedSuperBinding, cachedInfo->needsSuperBinding, cachedInfo->usesEval, cachedInfo->innerArrowFunctionFeatures);
functionInfo.body = context.createFunctionMetadata(
startLocation, endLocation, startColumn, bodyEndColumn,
functionKeywordStart, functionNameStart, parametersStart,
cachedInfo->strictMode, constructorKind, functionSuperBinding,
cachedInfo->parameterCount,
mode, functionBodyType == ArrowFunctionBodyExpression);
functionInfo.endOffset = cachedInfo->endFunctionOffset;
functionInfo.parameterCount = cachedInfo->parameterCount;
functionScope->restoreFromSourceProviderCache(cachedInfo);
popScope(functionScope, TreeBuilder::NeedsFreeVariableInfo);
m_token = cachedInfo->endFunctionToken();
if (endColumnIsOnStartLine)
m_token.m_location.lineStartOffset = currentLineStartOffset;
m_lexer->setOffset(m_token.m_location.endOffset, m_token.m_location.lineStartOffset);
m_lexer->setLineNumber(m_token.m_location.line);
switch (functionBodyType) {
case ArrowFunctionBodyExpression:
next();
context.setEndOffset(functionInfo.body, m_lexer->currentOffset());
break;
case ArrowFunctionBodyBlock:
case StandardFunctionBodyBlock:
context.setEndOffset(functionInfo.body, m_lexer->currentOffset());
next();
break;
}
functionInfo.endLine = m_lastTokenEndPosition.line;
return true;
}
return false;
};
SyntaxChecker syntaxChecker(const_cast<VM&>(m_vm), m_lexer.get());
if (UNLIKELY((SourceParseModeSet(SourceParseMode::ArrowFunctionMode, SourceParseMode::AsyncArrowFunctionMode).contains(mode)))) {
startLocation = tokenLocation();
functionInfo.startLine = tokenLine();
startColumn = tokenColumn();
parametersStart = m_token.m_location.startOffset;
functionInfo.startOffset = parametersStart;
functionInfo.parametersStartColumn = startColumn;
if (loadCachedFunction())
return true;
{
// Parse formal parameters with [+Yield] parameterization, in order to ban YieldExpressions
// in ArrowFormalParameters, per ES6 #sec-arrow-function-definitions-static-semantics-early-errors.
Scope::MaybeParseAsGeneratorForScope parseAsGenerator(functionScope, parentScope->isGenerator());
SetForScope<bool> overrideAllowAwait(m_parserState.allowAwait, !parentScope->isAsyncFunction() && !isAsyncFunctionParseMode(mode));
parseFunctionParameters(syntaxChecker, mode, functionInfo);
propagateError();
}
matchOrFail(ARROWFUNCTION, "Expected a '=>' after arrow function parameter declaration");
if (m_lexer->hasLineTerminatorBeforeToken())
failDueToUnexpectedToken();
ASSERT(constructorKind == ConstructorKind::None);
// Check if arrow body start with {. If it true it mean that arrow function is Fat arrow function
// and we need use common approach to parse function body
next();
functionBodyType = match(OPENBRACE) ? ArrowFunctionBodyBlock : ArrowFunctionBodyExpression;
} else {
// http://ecma-international.org/ecma-262/6.0/#sec-function-definitions
// FunctionExpression :
// function BindingIdentifieropt ( FormalParameters ) { FunctionBody }
//
// FunctionDeclaration[Yield, Default] :
// function BindingIdentifier[?Yield] ( FormalParameters ) { FunctionBody }
// [+Default] function ( FormalParameters ) { FunctionBody }
//
// GeneratorDeclaration[Yield, Default] :
// function * BindingIdentifier[?Yield] ( FormalParameters[Yield] ) { GeneratorBody }
// [+Default] function * ( FormalParameters[Yield] ) { GeneratorBody }
//
// GeneratorExpression :
// function * BindingIdentifier[Yield]opt ( FormalParameters[Yield] ) { GeneratorBody }
//
// The name of FunctionExpression and AsyncFunctionExpression can accept "yield" even in the context of generator.
bool upperScopeIsGenerator = false;
if (!(functionDefinitionType == FunctionDefinitionType::Expression && SourceParseModeSet(SourceParseMode::NormalFunctionMode, SourceParseMode::AsyncFunctionMode).contains(mode)))
upperScopeIsGenerator = upperScope(1)->isGenerator();
if (requirements != FunctionNameRequirements::Unnamed) {
ASSERT_WITH_MESSAGE(!(requirements == FunctionNameRequirements::None && !functionInfo.name), "When specifying FunctionNameRequirements::None, we need to initialize functionInfo.name with the default value in the caller side.");
if (matchSpecIdentifier(upperScopeIsGenerator)) {
functionInfo.name = m_token.m_data.ident;
m_parserState.lastFunctionName = functionInfo.name;
if (UNLIKELY(isDisallowedAwaitFunctionName))
semanticFailIfTrue(functionDefinitionType == FunctionDefinitionType::Declaration || isAsyncFunctionOrAsyncGeneratorWrapperParseMode(mode), "Cannot declare function named 'await' ", isDisallowedAwaitFunctionNameReason);
else if (isAsyncFunctionOrAsyncGeneratorWrapperParseMode(mode) && match(AWAIT) && functionDefinitionType == FunctionDefinitionType::Expression)
semanticFail("Cannot declare ", stringForFunctionMode(mode), " named 'await'");
else if (isGeneratorWrapperParseMode(mode) && match(YIELD) && functionDefinitionType == FunctionDefinitionType::Expression)
semanticFail("Cannot declare generator function named 'yield'");
next();
if (!nameIsInContainingScope)
failIfTrueIfStrict(functionScope->declareCallee(functionInfo.name) & DeclarationResult::InvalidStrictMode, "'", functionInfo.name->impl(), "' is not a valid ", stringForFunctionMode(mode), " name in strict mode");
} else if (requirements == FunctionNameRequirements::Named) {
if (match(OPENPAREN)) {
semanticFailIfTrue(mode == SourceParseMode::NormalFunctionMode, "Function statements must have a name");
semanticFailIfTrue(mode == SourceParseMode::AsyncFunctionMode, "Async function statements must have a name");
}
semanticFailureDueToKeyword(stringForFunctionMode(mode), " name");
failDueToUnexpectedToken();
return false;
}
ASSERT(functionInfo.name);
}
startLocation = tokenLocation();
functionInfo.startLine = tokenLine();
startColumn = tokenColumn();
functionInfo.parametersStartColumn = startColumn;
parametersStart = m_token.m_location.startOffset;
functionInfo.startOffset = parametersStart;
if (loadCachedFunction())
return true;
{
SetForScope<bool> overrideAllowAwait(m_parserState.allowAwait, !isAsyncFunctionParseMode(mode));
parseFunctionParameters(syntaxChecker, mode, functionInfo);
propagateError();
}
matchOrFail(OPENBRACE, "Expected an opening '{' at the start of a ", stringForFunctionMode(mode), " body");
// If the code is invoked from function constructor, we need to ensure that parameters are only composed by the string offered as parameters.
if (UNLIKELY(functionConstructorParametersEndPosition))
semanticFailIfFalse(lastTokenEndPosition().offset == *functionConstructorParametersEndPosition, "Parameters should match arguments offered as parameters in Function constructor");
// BytecodeGenerator emits code to throw TypeError when a class constructor is "call"ed.
// Set ConstructorKind to None for non-constructor methods of classes.
if (parentScope->isGlobalCodeScope() && m_defaultConstructorKindForTopLevelFunction != ConstructorKind::None) {
constructorKind = m_defaultConstructorKindForTopLevelFunction;
expectedSuperBinding = m_defaultConstructorKindForTopLevelFunction == ConstructorKind::Extends ? SuperBinding::Needed : SuperBinding::NotNeeded;
}
functionBodyType = StandardFunctionBodyBlock;
}
functionScope->setConstructorKind(constructorKind);
functionScope->setExpectedSuperBinding(expectedSuperBinding);
m_parserState.lastFunctionName = lastFunctionName;
ParserState oldState = internalSaveParserState(context);
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=156962
// This loop collects the set of capture candidates that aren't
// part of the set of this function's declared parameters. We will
// figure out which parameters are captured for this function when
// we actually generate code for it. For now, we just propagate to
// our parent scopes which variables we might have closed over that
// belong to them. This is necessary for correctness when using
// the source provider cache because we can't close over a variable
// that we don't claim to close over. The source provider cache must
// know this information to properly cache this function.
// This might work itself out nicer if we declared a different
// Scope struct for the parameters (because they are indeed implemented
// as their own scope).
UniquedStringImplPtrSet nonLocalCapturesFromParameterExpressions;
functionScope->forEachUsedVariable([&] (UniquedStringImpl* impl) {
if (!functionScope->hasDeclaredParameter(impl)) {
nonLocalCapturesFromParameterExpressions.add(impl);
if (TreeBuilder::NeedsFreeVariableInfo)
parentScope->addClosedVariableCandidateUnconditionally(impl);
}
});
auto performParsingFunctionBody = [&] {
return parseFunctionBody(context, syntaxChecker, startLocation, startColumn, functionKeywordStart, functionNameStart, parametersStart, constructorKind, expectedSuperBinding, functionBodyType, functionInfo.parameterCount, mode);
};
if (isGeneratorOrAsyncFunctionWrapperParseMode(mode)) {
AutoPopScopeRef generatorBodyScope(this, pushScope());
SourceParseMode innerParseMode = SourceParseMode::GeneratorBodyMode;
if (isAsyncFunctionOrAsyncGeneratorWrapperParseMode(mode))
innerParseMode = getAsynFunctionBodyParseMode(mode);
generatorBodyScope->setSourceParseMode(innerParseMode);
generatorBodyScope->setConstructorKind(ConstructorKind::None);
generatorBodyScope->setExpectedSuperBinding(expectedSuperBinding);
// Disallow 'use strict' directives in the implicit inner function if
// needed.
if (functionScope->hasNonSimpleParameterList())
generatorBodyScope->setHasNonSimpleParameterList();
functionInfo.body = performParsingFunctionBody();
// When a generator has a "use strict" directive, a generator function wrapping it should be strict mode.
if (generatorBodyScope->strictMode())
functionScope->setStrictMode();
popScope(generatorBodyScope, TreeBuilder::NeedsFreeVariableInfo);
} else
functionInfo.body = performParsingFunctionBody();
restoreParserState(context, oldState);
failIfFalse(functionInfo.body, "Cannot parse the body of this ", stringForFunctionMode(mode));
context.setEndOffset(functionInfo.body, m_lexer->currentOffset());
if (functionScope->strictMode() && requirements != FunctionNameRequirements::Unnamed) {
ASSERT(functionInfo.name);
RELEASE_ASSERT(SourceParseModeSet(SourceParseMode::NormalFunctionMode, SourceParseMode::MethodMode, SourceParseMode::ArrowFunctionMode, SourceParseMode::GeneratorBodyMode, SourceParseMode::GeneratorWrapperFunctionMode).contains(mode) || isAsyncFunctionOrAsyncGeneratorWrapperParseMode(mode));
semanticFailIfTrue(m_vm.propertyNames->arguments == *functionInfo.name, "'", functionInfo.name->impl(), "' is not a valid function name in strict mode");
semanticFailIfTrue(m_vm.propertyNames->eval == *functionInfo.name, "'", functionInfo.name->impl(), "' is not a valid function name in strict mode");
}
JSTokenLocation location = JSTokenLocation(m_token.m_location);
functionInfo.endOffset = m_token.m_data.offset;
if (functionBodyType == ArrowFunctionBodyExpression) {
location = locationBeforeLastToken();
functionInfo.endOffset = location.endOffset;
} else {
recordFunctionEntryLocation(JSTextPosition(startLocation.line, startLocation.startOffset, startLocation.lineStartOffset));
recordFunctionLeaveLocation(JSTextPosition(location.line, location.startOffset, location.lineStartOffset));
}
// Cache the tokenizer state and the function scope the first time the function is parsed.
// Any future reparsing can then skip the function.
// For arrow function is 8 = x=>x + 4 symbols;
// For ordinary function is 16 = function(){} + 4 symbols
const int minimumSourceLengthToCache = functionBodyType == StandardFunctionBodyBlock ? 16 : 8;
std::unique_ptr<SourceProviderCacheItem> newInfo;
int sourceLength = functionInfo.endOffset - functionInfo.startOffset;
if (TreeBuilder::CanUseFunctionCache && m_functionCache && sourceLength > minimumSourceLengthToCache) {
SourceProviderCacheItemCreationParameters parameters;
parameters.endFunctionOffset = functionInfo.endOffset;
parameters.lastTokenLine = location.line;
parameters.lastTokenStartOffset = location.startOffset;
parameters.lastTokenEndOffset = location.endOffset;
parameters.lastTokenLineStartOffset = location.lineStartOffset;
parameters.parameterCount = functionInfo.parameterCount;
parameters.constructorKind = constructorKind;
parameters.expectedSuperBinding = expectedSuperBinding;
if (functionBodyType == ArrowFunctionBodyExpression) {
parameters.isBodyArrowExpression = true;
parameters.tokenType = m_token.m_type;
}
functionScope->fillParametersForSourceProviderCache(parameters, nonLocalCapturesFromParameterExpressions);
newInfo = SourceProviderCacheItem::create(parameters);
}
bool functionScopeWasStrictMode = functionScope->strictMode();
popScope(functionScope, TreeBuilder::NeedsFreeVariableInfo);
if (functionBodyType != ArrowFunctionBodyExpression) {
matchOrFail(CLOSEBRACE, "Expected a closing '}' after a ", stringForFunctionMode(mode), " body");
next();
} else {
// We need to lex the last token again because the last token is lexed under the different context because of the following possibilities.
// 1. which may have different strict mode.
// 2. which may not build strings for tokens.
// But (1) is not possible because we do not recognize the string literal in ArrowFunctionBodyExpression as directive and this is correct in terms of the spec (`value => "use strict"`).
// So we only check TreeBuilder's type here.
ASSERT_UNUSED(functionScopeWasStrictMode, functionScopeWasStrictMode == currentScope()->strictMode());
if (!std::is_same<TreeBuilder, SyntaxChecker>::value)
lexCurrentTokenAgainUnderCurrentContext(context);
}
if (newInfo)
m_functionCache->add(functionInfo.startOffset, WTFMove(newInfo));
functionInfo.endLine = m_lastTokenEndPosition.line;
return true;
}
static NO_RETURN_DUE_TO_CRASH FunctionMetadataNode* getMetadata(ParserFunctionInfo<SyntaxChecker>&) { RELEASE_ASSERT_NOT_REACHED(); }
static FunctionMetadataNode* getMetadata(ParserFunctionInfo<ASTBuilder>& info) { return info.body; }
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseFunctionDeclaration(TreeBuilder& context, FunctionDeclarationType declarationType, ExportType exportType, DeclarationDefaultContext declarationDefaultContext, Optional<int> functionConstructorParametersEndPosition)
{
ASSERT(match(FUNCTION));
JSTokenLocation location(tokenLocation());
unsigned functionKeywordStart = tokenStart();
next();
SourceParseMode parseMode = SourceParseMode::NormalFunctionMode;
if (match(TIMES)) {
failIfTrue(declarationType == FunctionDeclarationType::Statement, "Cannot use generator function declaration in single-statement context");
next();
parseMode = SourceParseMode::GeneratorWrapperFunctionMode;
}
ParserFunctionInfo<TreeBuilder> functionInfo;
FunctionNameRequirements requirements = FunctionNameRequirements::Named;
if (declarationDefaultContext == DeclarationDefaultContext::ExportDefault) {
// Under the "export default" context, function declaration does not require the function name.
//
// ExportDeclaration:
// ...
// export default HoistableDeclaration[~Yield, +Default]
// ...
//
// HoistableDeclaration[Yield, Default]:
// FunctionDeclaration[?Yield, ?Default]
// GeneratorDeclaration[?Yield, ?Default]
//
// FunctionDeclaration[Yield, Default]:
// ...
// [+Default] function ( FormalParameters[~Yield] ) { FunctionBody[~Yield] }
//
// GeneratorDeclaration[Yield, Default]:
// ...
// [+Default] function * ( FormalParameters[+Yield] ) { GeneratorBody }
//
// In this case, we use "*default*" as this function declaration's name.
requirements = FunctionNameRequirements::None;
functionInfo.name = &m_vm.propertyNames->starDefaultPrivateName;
}
failIfFalse((parseFunctionInfo(context, requirements, parseMode, true, ConstructorKind::None, SuperBinding::NotNeeded, functionKeywordStart, functionInfo, FunctionDefinitionType::Declaration, functionConstructorParametersEndPosition)), "Cannot parse this function");
ASSERT(functionInfo.name);
std::pair<DeclarationResultMask, ScopeRef> functionDeclaration = declareFunction(functionInfo.name);
DeclarationResultMask declarationResult = functionDeclaration.first;
failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare a function named '", functionInfo.name->impl(), "' in strict mode");
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
internalFailWithMessage(false, "Cannot declare a function that shadows a let/const/class/function variable '", functionInfo.name->impl(), "' in strict mode");
if (exportType == ExportType::Exported) {
ASSERT_WITH_MESSAGE(declarationDefaultContext != DeclarationDefaultContext::ExportDefault, "Export default case will export the name and binding in the caller.");
semanticFailIfFalse(exportName(*functionInfo.name), "Cannot export a duplicate function name: '", functionInfo.name->impl(), "'");
m_moduleScopeData->exportBinding(*functionInfo.name);
}
TreeStatement result = context.createFuncDeclStatement(location, functionInfo);
if (TreeBuilder::CreatesAST)
functionDeclaration.second->appendFunction(getMetadata(functionInfo));
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseAsyncFunctionDeclaration(TreeBuilder& context, ExportType exportType, DeclarationDefaultContext declarationDefaultContext, Optional<int> functionConstructorParametersEndPosition)
{
ASSERT(match(FUNCTION));
JSTokenLocation location(tokenLocation());
unsigned functionKeywordStart = tokenStart();
next();
ParserFunctionInfo<TreeBuilder> functionInfo;
SourceParseMode parseMode = SourceParseMode::AsyncFunctionMode;
if (consume(TIMES))
parseMode = SourceParseMode::AsyncGeneratorWrapperFunctionMode;
FunctionNameRequirements requirements = FunctionNameRequirements::Named;
if (declarationDefaultContext == DeclarationDefaultContext::ExportDefault) {
// Under the "export default" context, function declaration does not require the function name.
//
// ExportDeclaration:
// ...
// export default HoistableDeclaration[~Yield, +Default]
// ...
//
// HoistableDeclaration[Yield, Default]:
// FunctionDeclaration[?Yield, ?Default]
// GeneratorDeclaration[?Yield, ?Default]
//
// FunctionDeclaration[Yield, Default]:
// ...
// [+Default] function ( FormalParameters[~Yield] ) { FunctionBody[~Yield] }
//
// GeneratorDeclaration[Yield, Default]:
// ...
// [+Default] function * ( FormalParameters[+Yield] ) { GeneratorBody }
//
// In this case, we use "*default*" as this function declaration's name.
requirements = FunctionNameRequirements::None;
functionInfo.name = &m_vm.propertyNames->starDefaultPrivateName;
}
failIfFalse((parseFunctionInfo(context, requirements, parseMode, true, ConstructorKind::None, SuperBinding::NotNeeded, functionKeywordStart, functionInfo, FunctionDefinitionType::Declaration, functionConstructorParametersEndPosition)), "Cannot parse this async function");
failIfFalse(functionInfo.name, "Async function statements must have a name");
std::pair<DeclarationResultMask, ScopeRef> functionDeclaration = declareFunction(functionInfo.name);
DeclarationResultMask declarationResult = functionDeclaration.first;
failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare an async function named '", functionInfo.name->impl(), "' in strict mode");
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
internalFailWithMessage(false, "Cannot declare an async function that shadows a let/const/class/function variable '", functionInfo.name->impl(), "' in strict mode");
if (exportType == ExportType::Exported) {
semanticFailIfFalse(exportName(*functionInfo.name), "Cannot export a duplicate function name: '", functionInfo.name->impl(), "'");
m_moduleScopeData->exportBinding(*functionInfo.name);
}
TreeStatement result = context.createFuncDeclStatement(location, functionInfo);
if (TreeBuilder::CreatesAST)
functionDeclaration.second->appendFunction(getMetadata(functionInfo));
return result;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseClassDeclaration(TreeBuilder& context, ExportType exportType, DeclarationDefaultContext declarationDefaultContext)
{
ASSERT(match(CLASSTOKEN));
JSTokenLocation location(tokenLocation());
JSTextPosition classStart = tokenStartPosition();
unsigned classStartLine = tokenLine();
ParserClassInfo<TreeBuilder> info;
FunctionNameRequirements requirements = FunctionNameRequirements::Named;
if (declarationDefaultContext == DeclarationDefaultContext::ExportDefault) {
// Under the "export default" context, class declaration does not require the class name.
//
// ExportDeclaration:
// ...
// export default ClassDeclaration[~Yield, +Default]
// ...
//
// ClassDeclaration[Yield, Default]:
// ...
// [+Default] class ClassTail[?Yield]
//
// In this case, we use "*default*" as this class declaration's name.
requirements = FunctionNameRequirements::None;
info.className = &m_vm.propertyNames->starDefaultPrivateName;
}
TreeClassExpression classExpr = parseClass(context, requirements, info);
failIfFalse(classExpr, "Failed to parse class");
ASSERT(info.className);
DeclarationResultMask declarationResult = declareVariable(info.className, DeclarationType::LetDeclaration);
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
internalFailWithMessage(false, "Cannot declare a class twice: '", info.className->impl(), "'");
if (exportType == ExportType::Exported) {
ASSERT_WITH_MESSAGE(declarationDefaultContext != DeclarationDefaultContext::ExportDefault, "Export default case will export the name and binding in the caller.");
semanticFailIfFalse(exportName(*info.className), "Cannot export a duplicate class name: '", info.className->impl(), "'");
m_moduleScopeData->exportBinding(*info.className);
}
JSTextPosition classEnd = lastTokenEndPosition();
unsigned classEndLine = tokenLine();
return context.createClassDeclStatement(location, classExpr, classStart, classEnd, classStartLine, classEndLine);
}
static constexpr ASCIILiteral instanceComputedNamePrefix { "instanceComputedName"_s };
static constexpr ASCIILiteral staticComputedNamePrefix { "staticComputedName"_s };
template <typename LexerType>
template <class TreeBuilder> TreeClassExpression Parser<LexerType>::parseClass(TreeBuilder& context, FunctionNameRequirements requirements, ParserClassInfo<TreeBuilder>& info)
{
ASSERT(match(CLASSTOKEN));
JSTokenLocation location(tokenLocation());
info.startLine = location.line;
info.startColumn = tokenColumn();
info.startOffset = location.startOffset;
next();
AutoPopScopeRef classScope(this, pushScope());
classScope->setIsLexicalScope();
classScope->preventVarDeclarations();
classScope->setStrictMode();
ASSERT_WITH_MESSAGE(requirements != FunctionNameRequirements::Unnamed, "Currently, there is no caller that uses FunctionNameRequirements::Unnamed for class syntax.");
ASSERT_WITH_MESSAGE(!(requirements == FunctionNameRequirements::None && !info.className), "When specifying FunctionNameRequirements::None, we need to initialize info.className with the default value in the caller side.");
if (match(IDENT)) {
info.className = m_token.m_data.ident;
next();
failIfTrue(classScope->declareLexicalVariable(info.className, true) & DeclarationResult::InvalidStrictMode, "'", info.className->impl(), "' is not a valid class name");
} else if (requirements == FunctionNameRequirements::Named) {
if (match(OPENBRACE))
semanticFail("Class statements must have a name");
semanticFailureDueToKeyword("class name");
failDueToUnexpectedToken();
}
ASSERT(info.className);
TreeExpression parentClass = 0;
if (consume(EXTENDS)) {
parentClass = parseMemberExpression(context);
failIfFalse(parentClass, "Cannot parse the parent class name");
}
classScope->setIsClassScope();
const ConstructorKind constructorKind = parentClass ? ConstructorKind::Extends : ConstructorKind::Base;
consumeOrFail(OPENBRACE, "Expected opening '{' at the start of a class body");
TreeExpression constructor = 0;
TreePropertyList classElements = 0;
TreePropertyList classElementsTail = 0;
unsigned nextInstanceComputedFieldID = 0;
unsigned nextStaticComputedFieldID = 0;
while (!match(CLOSEBRACE)) {
if (match(SEMICOLON)) {
next();
continue;
}
JSTokenLocation methodLocation(tokenLocation());
unsigned methodStart = tokenStart();
// For backwards compatibility, "static" is a non-reserved keyword in non-strict mode.
ClassElementTag tag = ClassElementTag::Instance;
auto type = PropertyNode::Constant;
if (match(RESERVED_IF_STRICT) && *m_token.m_data.ident == m_vm.propertyNames->staticKeyword) {
SavePoint savePoint = createSavePoint(context);
next();
if (match(OPENPAREN) || match(SEMICOLON) || match(EQUAL)) {
// Reparse "static()" as a method or "static" as a class field.
restoreSavePoint(context, savePoint);
} else
tag = ClassElementTag::Static;
}
// FIXME: Figure out a way to share more code with parseProperty.
const CommonIdentifiers& propertyNames = *m_vm.propertyNames;
const Identifier* ident = &propertyNames.nullIdentifier;
TreeExpression computedPropertyName = 0;
bool isGetter = false;
bool isSetter = false;
SourceParseMode parseMode = SourceParseMode::MethodMode;
if (consume(TIMES))
parseMode = SourceParseMode::GeneratorWrapperMethodMode;
parseMethod:
switch (m_token.m_type) {
namedKeyword:
case STRING:
ident = m_token.m_data.ident;
ASSERT(ident);
next();
break;
case BIGINT:
ident = &m_parserArena.identifierArena().makeBigIntDecimalIdentifier(const_cast<VM&>(m_vm), *m_token.m_data.bigIntString, m_token.m_data.radix);
ASSERT(ident);
next();
break;
case ESCAPED_KEYWORD:
case IDENT:
if (UNLIKELY(*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped)) {
if (!isGeneratorMethodParseMode(parseMode) && !isAsyncMethodParseMode(parseMode)) {
ident = m_token.m_data.ident;
next();
// We match SEMICOLON as a special case for a field called 'async' without initializer.
if (match(OPENPAREN) || match(COLON) || match(SEMICOLON) || match(EQUAL) || m_lexer->hasLineTerminatorBeforeToken())
break;
if (UNLIKELY(consume(TIMES)))
parseMode = SourceParseMode::AsyncGeneratorWrapperMethodMode;
else
parseMode = SourceParseMode::AsyncMethodMode;
goto parseMethod;
}
}
FALLTHROUGH;
case AWAIT: {
ident = m_token.m_data.ident;
bool escaped = m_token.m_data.escaped;
ASSERT(ident);
next();
if (parseMode == SourceParseMode::MethodMode && !escaped && (matchIdentifierOrKeyword() || match(STRING) || match(DOUBLE) || match(INTEGER) || match(BIGINT) || match(OPENBRACKET))) {
isGetter = *ident == propertyNames.get;
isSetter = *ident == propertyNames.set;
}
break;
}
case DOUBLE:
case INTEGER:
ident = &m_parserArena.identifierArena().makeNumericIdentifier(const_cast<VM&>(m_vm), m_token.m_data.doubleValue);
ASSERT(ident);
next();
break;
case OPENBRACKET:
next();
computedPropertyName = parseAssignmentExpression(context);
type = static_cast<PropertyNode::Type>(type | PropertyNode::Computed);
failIfFalse(computedPropertyName, "Cannot parse computed property name");
handleProductionOrFail(CLOSEBRACKET, "]", "end", "computed property name");
break;
case PRIVATENAME: {
ASSERT(Options::usePrivateClassFields());
JSToken token = m_token;
ident = m_token.m_data.ident;
if (!Options::usePrivateStaticClassFields())
failIfTrue(tag == ClassElementTag::Static, "Static class element cannot be private");
failIfTrue(isGetter || isSetter, "Cannot parse class method with private name");
ASSERT(ident);
next();
failIfTrue(matchAndUpdate(OPENPAREN, token), "Cannot parse class method with private name");
semanticFailIfTrue(classScope->declarePrivateName(*ident) & DeclarationResult::InvalidDuplicateDeclaration, "Cannot declare private field twice");
type = static_cast<PropertyNode::Type>(type | PropertyNode::Private);
break;
}
default:
if (m_token.m_type & KeywordTokenFlag)
goto namedKeyword;
failDueToUnexpectedToken();
}
TreeProperty property;
if (isGetter || isSetter) {
type = static_cast<PropertyNode::Type>(type & ~PropertyNode::Constant);
type = static_cast<PropertyNode::Type>(type | (isGetter ? PropertyNode::Getter : PropertyNode::Setter));
property = parseGetterSetter(context, type, methodStart, ConstructorKind::None, tag);
failIfFalse(property, "Cannot parse this method");
} else if (!match(OPENPAREN) && (tag == ClassElementTag::Instance || Options::usePublicStaticClassFields()) && parseMode == SourceParseMode::MethodMode) {
ASSERT(!isGetter && !isSetter);
if (ident) {
semanticFailIfTrue(*ident == propertyNames.constructor, "Cannot declare class field named 'constructor'");
semanticFailIfTrue(*ident == propertyNames.constructorPrivateField, "Cannot declare private class field named '#constructor'");
if (tag == ClassElementTag::Static)
semanticFailIfTrue(*ident == propertyNames.prototype, "Cannot declare a static field named 'prototype'");
}
if (computedPropertyName) {
if (tag == ClassElementTag::Instance)
ident = &m_parserArena.identifierArena().makePrivateIdentifier(m_vm, instanceComputedNamePrefix, nextInstanceComputedFieldID++);
else
ident = &m_parserArena.identifierArena().makePrivateIdentifier(m_vm, staticComputedNamePrefix, nextStaticComputedFieldID++);
DeclarationResultMask declarationResult = classScope->declareLexicalVariable(ident, true);
ASSERT_UNUSED(declarationResult, declarationResult == DeclarationResult::Valid);
classScope->useVariable(ident, false);
classScope->addClosedVariableCandidateUnconditionally(ident->impl());
}
TreeExpression initializer = 0;
if (consume(EQUAL)) {
SetForScope<bool> overrideParsingClassFieldInitializer(m_parserState.isParsingClassFieldInitializer, true);
classScope->setExpectedSuperBinding(SuperBinding::Needed);
initializer = parseAssignmentExpression(context);
classScope->setExpectedSuperBinding(SuperBinding::NotNeeded);
failIfFalse(initializer, "Cannot parse initializer for class field");
classScope->markLastUsedVariablesSetAsCaptured();
}
failIfFalse(autoSemiColon(), "Expected a ';' following a class field");
auto inferName = initializer ? InferName::Allowed : InferName::Disallowed;
if (computedPropertyName)
property = context.createProperty(ident, computedPropertyName, initializer, type, SuperBinding::NotNeeded, tag);
else
property = context.createProperty(ident, initializer, type, SuperBinding::NotNeeded, inferName, tag);
} else {
ParserFunctionInfo<TreeBuilder> methodInfo;
bool isConstructor = tag == ClassElementTag::Instance && *ident == propertyNames.constructor;
semanticFailIfTrue(isConstructor && parseMode != SourceParseMode::MethodMode,
"Cannot declare ", stringArticleForFunctionMode(parseMode), stringForFunctionMode(parseMode), " named 'constructor'");
methodInfo.name = isConstructor ? info.className : ident;
failIfFalse((parseFunctionInfo(context, FunctionNameRequirements::Unnamed, parseMode, false, isConstructor ? constructorKind : ConstructorKind::None, SuperBinding::Needed, methodStart, methodInfo, FunctionDefinitionType::Method)), "Cannot parse this method");
TreeExpression method = context.createMethodDefinition(methodLocation, methodInfo);
if (isConstructor) {
semanticFailIfTrue(constructor, "Cannot declare multiple constructors in a single class");
constructor = method;
continue;
}
semanticFailIfTrue(tag == ClassElementTag::Static && methodInfo.name && *methodInfo.name == propertyNames.prototype,
"Cannot declare a static method named 'prototype'");
if (computedPropertyName) {
property = context.createProperty(computedPropertyName, method, type, SuperBinding::Needed, tag);
} else {
property = context.createProperty(methodInfo.name, method, type, SuperBinding::Needed, InferName::Allowed, tag);
}
}
if (classElementsTail)
classElementsTail = context.createPropertyList(methodLocation, property, classElementsTail);
else
classElements = classElementsTail = context.createPropertyList(methodLocation, property);
}
info.endOffset = tokenLocation().endOffset - 1;
consumeOrFail(CLOSEBRACE, "Expected a closing '}' after a class body");
if (Options::usePrivateClassFields()) {
// Fail if there are no parent private name scopes and any used-but-undeclared private names.
semanticFailIfFalse(copyUndeclaredPrivateNamesToOuterScope(), "Cannot reference undeclared private names");
}
auto classExpression = context.createClassExpr(location, info, classScope->finalizeLexicalEnvironment(), constructor, parentClass, classElements);
popScope(classScope, TreeBuilder::NeedsFreeVariableInfo);
return classExpression;
}
template <typename LexerType>
template <class TreeBuilder> TreeSourceElements Parser<LexerType>::parseClassFieldInitializerSourceElements(TreeBuilder& context, const Vector<JSTextPosition>& classFieldLocations)
{
TreeSourceElements sourceElements = context.createSourceElements();
currentScope()->setIsClassScope();
unsigned numComputedFields = 0;
for (auto location : classFieldLocations) {
// This loop will either parse only static fields or only
// instance fields, but never a mix; we could make it slightly
// smarter about parsing given that fact, but it's probably
// not worth the hassle, so begin each iteration without
// knowing which kind the next field will be.
bool isStaticField = false;
// We don't need to worry about hasLineTerminatorBeforeToken
// on class fields, so we set this value to false.
LexerState lexerState { location.offset, static_cast<unsigned>(location.lineStartOffset), static_cast<unsigned>(location.line), static_cast<unsigned>(location.line), false };
restoreLexerState(lexerState);
JSTokenLocation fieldLocation = tokenLocation();
const Identifier* ident = nullptr;
DefineFieldNode::Type type = DefineFieldNode::Type::Name;
if (match(RESERVED_IF_STRICT) && *m_token.m_data.ident == m_vm.propertyNames->staticKeyword) {
auto* staticIdentifier = m_token.m_data.ident;
ASSERT(staticIdentifier);
next();
if (match(SEMICOLON) || match (EQUAL) || match(CLOSEBRACE) || m_lexer->hasLineTerminatorBeforeToken())
ident = staticIdentifier;
else
isStaticField = true;
}
if (!ident) {
switch (m_token.m_type) {
case PRIVATENAME:
type = DefineFieldNode::Type::PrivateName;
FALLTHROUGH;
case STRING:
case IDENT:
namedKeyword:
ident = m_token.m_data.ident;
ASSERT(ident);
next();
break;
case BIGINT:
ident = &m_parserArena.identifierArena().makeBigIntDecimalIdentifier(const_cast<VM&>(m_vm), *m_token.m_data.bigIntString, m_token.m_data.radix);
ASSERT(ident);
next();
break;
case DOUBLE:
case INTEGER:
ident = &m_parserArena.identifierArena().makeNumericIdentifier(const_cast<VM&>(m_vm), m_token.m_data.doubleValue);
ASSERT(ident);
next();
break;
case OPENBRACKET: {
next();
TreeExpression computedPropertyName = parseAssignmentExpression(context);
failIfFalse(computedPropertyName, "Cannot parse computed property name");
handleProductionOrFail(CLOSEBRACKET, "]", "end", "computed property name");
ident = &m_parserArena.identifierArena().makePrivateIdentifier(m_vm,
isStaticField ? staticComputedNamePrefix : instanceComputedNamePrefix,
numComputedFields++);
type = DefineFieldNode::Type::ComputedName;
break;
}
default:
if (m_token.m_type & KeywordTokenFlag)
goto namedKeyword;
failDueToUnexpectedToken();
}
}
// Only valid class fields are handled in this function.
ASSERT(match(EQUAL) || match(SEMICOLON) || match(CLOSEBRACE) || m_lexer->hasLineTerminatorBeforeToken());
TreeExpression initializer = 0;
if (consume(EQUAL))
initializer = parseAssignmentExpression(context);
if (type == DefineFieldNode::Type::PrivateName)
currentScope()->useVariable(ident, false);
TreeStatement defineField = context.createDefineField(fieldLocation, ident, initializer, type);
context.appendStatement(sourceElements, defineField);
}
ASSERT(!hasError());
// Trick parseInner() into believing we've parsed the entire SourceCode, in order to prevent it from producing an error.
m_token.m_type = EOFTOK;
return sourceElements;
}
struct LabelInfo {
LabelInfo(const Identifier* ident, const JSTextPosition& start, const JSTextPosition& end)
: m_ident(ident)
, m_start(start)
, m_end(end)
{
}
const Identifier* m_ident;
JSTextPosition m_start;
JSTextPosition m_end;
};
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseExpressionOrLabelStatement(TreeBuilder& context, bool allowFunctionDeclarationAsStatement)
{
/* Expression and Label statements are ambiguous at LL(1), so we have a
* special case that looks for a colon as the next character in the input.
*/
Vector<LabelInfo> labels;
JSTokenLocation location;
do {
JSTextPosition start = tokenStartPosition();
location = tokenLocation();
if (!nextTokenIsColon()) {
// If we hit this path we're making a expression statement, which
// by definition can't make use of continue/break so we can just
// ignore any labels we might have accumulated.
TreeExpression expression = parseExpression(context, IsOnlyChildOfStatement::Yes);
failIfFalse(expression, "Cannot parse expression statement");
if (!autoSemiColon())
failDueToUnexpectedToken();
return context.createExprStatement(location, expression, start, m_lastTokenEndPosition.line);
}
semanticFailIfTrue(isDisallowedIdentifierAwait(m_token), "Cannot use 'await' as a label ", disallowedIdentifierAwaitReason());
semanticFailIfTrue(isDisallowedIdentifierYield(m_token), "Cannot use 'yield' as a label ", disallowedIdentifierYieldReason());
const Identifier* ident = m_token.m_data.ident;
JSTextPosition end = tokenEndPosition();
next();
consumeOrFail(COLON, "Labels must be followed by a ':'");
// This is O(N^2) over the current list of consecutive labels, but I
// have never seen more than one label in a row in the real world.
for (size_t i = 0; i < labels.size(); i++)
failIfTrue(ident->impl() == labels[i].m_ident->impl(), "Attempted to redeclare the label '", ident->impl(), "'");
failIfTrue(getLabel(ident), "Cannot find scope for the label '", ident->impl(), "'");
labels.append(LabelInfo(ident, start, end));
} while (matchSpecIdentifier());
bool isLoop = false;
switch (m_token.m_type) {
case FOR:
case WHILE:
case DO:
isLoop = true;
break;
default:
break;
}
const Identifier* unused = nullptr;
ScopeRef labelScope = currentScope();
for (size_t i = 0; i < labels.size(); i++)
pushLabel(labels[i].m_ident, isLoop);
m_immediateParentAllowsFunctionDeclarationInStatement = allowFunctionDeclarationAsStatement;
TreeStatement statement = parseStatement(context, unused);
for (size_t i = 0; i < labels.size(); i++)
popLabel(labelScope);
failIfFalse(statement, "Cannot parse statement");
for (size_t i = 0; i < labels.size(); i++) {
const LabelInfo& info = labels[labels.size() - i - 1];
statement = context.createLabelStatement(location, info.m_ident, statement, info.m_start, info.m_end);
}
return statement;
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseExpressionStatement(TreeBuilder& context)
{
switch (m_token.m_type) {
// Consult: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-expression-statement
// The ES6 spec mandates that we should fail from FUNCTION token here. We handle this case
// in parseStatement() which is the only caller of parseExpressionStatement().
// We actually allow FUNCTION in situations where it should not be allowed unless we're in strict mode.
case CLASSTOKEN:
failWithMessage("'class' declaration is not directly within a block statement");
break;
default:
// FIXME: when implementing 'let' we should fail when we see the token sequence "let [".
// https://bugs.webkit.org/show_bug.cgi?id=142944
break;
}
JSTextPosition start = tokenStartPosition();
JSTokenLocation location(tokenLocation());
TreeExpression expression = parseExpression(context, IsOnlyChildOfStatement::Yes);
failIfFalse(expression, "Cannot parse expression statement");
failIfFalse(autoSemiColon(), "Parse error");
return context.createExprStatement(location, expression, start, m_lastTokenEndPosition.line);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseIfStatement(TreeBuilder& context)
{
ASSERT(match(IF));
JSTokenLocation ifLocation(tokenLocation());
int start = tokenLine();
next();
handleProductionOrFail2(OPENPAREN, "(", "start", "'if' condition");
TreeExpression condition = parseExpression(context);
failIfFalse(condition, "Expected an expression as the condition for an if statement");
recordPauseLocation(context.breakpointLocation(condition));
int end = tokenLine();
handleProductionOrFail2(CLOSEPAREN, ")", "end", "'if' condition");
const Identifier* unused = nullptr;
m_immediateParentAllowsFunctionDeclarationInStatement = true;
TreeStatement trueBlock = parseStatement(context, unused);
failIfFalse(trueBlock, "Expected a statement as the body of an if block");
if (!match(ELSE))
return context.createIfStatement(ifLocation, condition, trueBlock, 0, start, end);
Vector<TreeExpression> exprStack;
Vector<std::pair<int, int>> posStack;
Vector<JSTokenLocation> tokenLocationStack;
Vector<TreeStatement> statementStack;
bool trailingElse = false;
do {
JSTokenLocation tempLocation = tokenLocation();
next();
if (!match(IF)) {
const Identifier* unused = nullptr;
m_immediateParentAllowsFunctionDeclarationInStatement = true;
TreeStatement block = parseStatement(context, unused);
failIfFalse(block, "Expected a statement as the body of an else block");
statementStack.append(block);
trailingElse = true;
break;
}
int innerStart = tokenLine();
next();
handleProductionOrFail2(OPENPAREN, "(", "start", "'if' condition");
TreeExpression innerCondition = parseExpression(context);
failIfFalse(innerCondition, "Expected an expression as the condition for an if statement");
recordPauseLocation(context.breakpointLocation(innerCondition));
int innerEnd = tokenLine();
handleProductionOrFail2(CLOSEPAREN, ")", "end", "'if' condition");
const Identifier* unused = nullptr;
m_immediateParentAllowsFunctionDeclarationInStatement = true;
TreeStatement innerTrueBlock = parseStatement(context, unused);
failIfFalse(innerTrueBlock, "Expected a statement as the body of an if block");
tokenLocationStack.append(tempLocation);
exprStack.append(innerCondition);
posStack.append(std::make_pair(innerStart, innerEnd));
statementStack.append(innerTrueBlock);
} while (match(ELSE));
if (!trailingElse) {
TreeExpression condition = exprStack.last();
exprStack.removeLast();
TreeStatement trueBlock = statementStack.last();
statementStack.removeLast();
std::pair<int, int> pos = posStack.last();
posStack.removeLast();
JSTokenLocation elseLocation = tokenLocationStack.last();
tokenLocationStack.removeLast();
TreeStatement ifStatement = context.createIfStatement(elseLocation, condition, trueBlock, 0, pos.first, pos.second);
context.setEndOffset(ifStatement, context.endOffset(trueBlock));
statementStack.append(ifStatement);
}
while (!exprStack.isEmpty()) {
TreeExpression condition = exprStack.last();
exprStack.removeLast();
TreeStatement falseBlock = statementStack.last();
statementStack.removeLast();
TreeStatement trueBlock = statementStack.last();
statementStack.removeLast();
std::pair<int, int> pos = posStack.last();
posStack.removeLast();
JSTokenLocation elseLocation = tokenLocationStack.last();
tokenLocationStack.removeLast();
TreeStatement ifStatement = context.createIfStatement(elseLocation, condition, trueBlock, falseBlock, pos.first, pos.second);
context.setEndOffset(ifStatement, context.endOffset(falseBlock));
statementStack.append(ifStatement);
}
return context.createIfStatement(ifLocation, condition, trueBlock, statementStack.last(), start, end);
}
template <typename LexerType>
template <class TreeBuilder> typename TreeBuilder::ModuleName Parser<LexerType>::parseModuleName(TreeBuilder& context)
{
// ModuleName (ModuleSpecifier in the spec) represents the module name imported by the script.
// http://www.ecma-international.org/ecma-262/6.0/#sec-imports
// http://www.ecma-international.org/ecma-262/6.0/#sec-exports
JSTokenLocation specifierLocation(tokenLocation());
failIfFalse(match(STRING), "Imported modules names must be string literals");
const Identifier* moduleName = m_token.m_data.ident;
next();
return context.createModuleName(specifierLocation, *moduleName);
}
template <typename LexerType>
template <class TreeBuilder> typename TreeBuilder::ImportSpecifier Parser<LexerType>::parseImportClauseItem(TreeBuilder& context, ImportSpecifierType specifierType)
{
// Produced node is the item of the ImportClause.
// That is the ImportSpecifier, ImportedDefaultBinding or NameSpaceImport.
// http://www.ecma-international.org/ecma-262/6.0/#sec-imports
JSTokenLocation specifierLocation(tokenLocation());
JSToken localNameToken;
const Identifier* importedName = nullptr;
const Identifier* localName = nullptr;
switch (specifierType) {
case ImportSpecifierType::NamespaceImport: {
// NameSpaceImport :
// * as ImportedBinding
// e.g.
// * as namespace
ASSERT(match(TIMES));
importedName = &m_vm.propertyNames->timesIdentifier;
next();
failIfFalse(matchContextualKeyword(m_vm.propertyNames->as), "Expected 'as' before imported binding name");
next();
failIfFalse(matchSpecIdentifier(), "Expected a variable name for the import declaration");
localNameToken = m_token;
localName = m_token.m_data.ident;
next();
break;
}
case ImportSpecifierType::NamedImport: {
// ImportSpecifier :
// ImportedBinding
// IdentifierName as ImportedBinding
// ModuleExportName as ImportedBinding
// e.g.
// A
// A as B
ASSERT(matchIdentifierOrKeyword() || match(STRING));
bool isModuleExportName = match(STRING);
localName = m_token.m_data.ident;
importedName = localName;
localNameToken = m_token;
if (isModuleExportName)
failIfTrue(hasUnpairedSurrogate(localName->string()), "Expected a well-formed-unicode string for the module export name");
next();
bool useAs = matchContextualKeyword(m_vm.propertyNames->as);
if (isModuleExportName)
failIfFalse(useAs, "Expected 'as' after the module export name string");
if (useAs) {
next();
failIfFalse(matchSpecIdentifier(), "Expected a variable name for the import declaration");
localNameToken = m_token;
localName = m_token.m_data.ident;
next();
}
break;
}
case ImportSpecifierType::DefaultImport: {
// ImportedDefaultBinding :
// ImportedBinding
ASSERT(matchSpecIdentifier());
localNameToken = m_token;
localName = m_token.m_data.ident;
importedName = &m_vm.propertyNames->defaultKeyword;
next();
break;
}
}
semanticFailIfTrue(localNameToken.m_type == AWAIT, "Cannot use 'await' as an imported binding name");
semanticFailIfTrue(localNameToken.m_type & KeywordTokenFlag, "Cannot use keyword as imported binding name");
DeclarationResultMask declarationResult = declareVariable(localName, DeclarationType::ConstDeclaration, (specifierType == ImportSpecifierType::NamespaceImport) ? DeclarationImportType::ImportedNamespace : DeclarationImportType::Imported);
if (declarationResult != DeclarationResult::Valid) {
failIfTrueIfStrict(declarationResult & DeclarationResult::InvalidStrictMode, "Cannot declare an imported binding named ", localName->impl(), " in strict mode");
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
internalFailWithMessage(false, "Cannot declare an imported binding name twice: '", localName->impl(), "'");
}
return context.createImportSpecifier(specifierLocation, *importedName, *localName);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseImportDeclaration(TreeBuilder& context)
{
// http://www.ecma-international.org/ecma-262/6.0/#sec-imports
ASSERT(match(IMPORT));
JSTokenLocation importLocation(tokenLocation());
next();
auto specifierList = context.createImportSpecifierList();
if (match(STRING)) {
// import ModuleSpecifier ;
auto moduleName = parseModuleName(context);
failIfFalse(moduleName, "Cannot parse the module name");
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted import declaration");
return context.createImportDeclaration(importLocation, specifierList, moduleName);
}
bool isFinishedParsingImport = false;
if (matchSpecIdentifier()) {
// ImportedDefaultBinding :
// ImportedBinding
auto specifier = parseImportClauseItem(context, ImportSpecifierType::DefaultImport);
failIfFalse(specifier, "Cannot parse the default import");
context.appendImportSpecifier(specifierList, specifier);
if (match(COMMA))
next();
else
isFinishedParsingImport = true;
}
if (!isFinishedParsingImport) {
if (match(TIMES)) {
// import NameSpaceImport FromClause ;
auto specifier = parseImportClauseItem(context, ImportSpecifierType::NamespaceImport);
failIfFalse(specifier, "Cannot parse the namespace import");
context.appendImportSpecifier(specifierList, specifier);
} else if (match(OPENBRACE)) {
// NamedImports :
// { }
// { ImportsList }
// { ImportsList , }
next();
while (!match(CLOSEBRACE)) {
failIfFalse(matchIdentifierOrKeyword() || match(STRING), "Expected an imported name or a module export name string for the import declaration");
auto specifier = parseImportClauseItem(context, ImportSpecifierType::NamedImport);
failIfFalse(specifier, "Cannot parse the named import");
context.appendImportSpecifier(specifierList, specifier);
if (!consume(COMMA))
break;
}
handleProductionOrFail2(CLOSEBRACE, "}", "end", "import list");
} else
failWithMessage("Expected namespace import or import list");
}
// FromClause :
// from ModuleSpecifier
failIfFalse(matchContextualKeyword(m_vm.propertyNames->from), "Expected 'from' before imported module name");
next();
auto moduleName = parseModuleName(context);
failIfFalse(moduleName, "Cannot parse the module name");
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted import declaration");
return context.createImportDeclaration(importLocation, specifierList, moduleName);
}
template <typename LexerType>
template <class TreeBuilder> typename TreeBuilder::ExportSpecifier Parser<LexerType>::parseExportSpecifier(TreeBuilder& context, Vector<std::pair<const Identifier*, const Identifier*>>& maybeExportedLocalNames, bool& hasKeywordForLocalBindings, bool& hasReferencedModuleExportNames)
{
// ExportSpecifier :
// IdentifierName
// IdentifierName as IdentifierName
// IdentifierName as ModuleExportName
// ModuleExportName
// ModuleExportName as IdentifierName
// ModuleExportName as ModuleExportName
// http://www.ecma-international.org/ecma-262/6.0/#sec-exports
ASSERT(matchIdentifierOrKeyword() || match(STRING));
JSTokenLocation specifierLocation(tokenLocation());
const Identifier* localName = m_token.m_data.ident;
const Identifier* exportedName = localName;
if (match(STRING)) {
hasReferencedModuleExportNames = true;
failIfTrue(hasUnpairedSurrogate(exportedName->string()), "Expected a well-formed-unicode string for the module export name");
} else {
if (m_token.m_type & KeywordTokenFlag)
hasKeywordForLocalBindings = true;
}
next();
if (matchContextualKeyword(m_vm.propertyNames->as)) {
next();
failIfFalse(matchIdentifierOrKeyword() || match(STRING), "Expected an exported name or a module export name string for the export declaration");
exportedName = m_token.m_data.ident;
if (match(STRING))
failIfTrue(hasUnpairedSurrogate(exportedName->string()), "Expected a well-formed-unicode string for the module export name");
next();
}
semanticFailIfFalse(exportName(*exportedName), "Cannot export a duplicate name '", exportedName->impl(), "'");
maybeExportedLocalNames.append(std::make_pair(localName, exportedName));
return context.createExportSpecifier(specifierLocation, *localName, *exportedName);
}
template <typename LexerType>
template <class TreeBuilder> TreeStatement Parser<LexerType>::parseExportDeclaration(TreeBuilder& context)
{
// http://www.ecma-international.org/ecma-262/6.0/#sec-exports
ASSERT(match(EXPORT_));
JSTokenLocation exportLocation(tokenLocation());
next();
switch (m_token.m_type) {
case TIMES: {
// export * FromClause ;
// export * as IdentifierName FromClause ;
// export * as ModuleExportName FromClause ;
next();
const Identifier* exportedName = nullptr;
JSTokenLocation specifierLocation;
if (matchContextualKeyword(m_vm.propertyNames->as)) {
next();
specifierLocation = JSTokenLocation(tokenLocation());
failIfFalse(matchIdentifierOrKeyword() || match(STRING), "Expected an exported name or a module export name string for the export declaration");
exportedName = m_token.m_data.ident;
if (match(STRING))
failIfTrue(hasUnpairedSurrogate(exportedName->string()), "Expected a well-formed-unicode string for the module export name");
next();
}
failIfFalse(matchContextualKeyword(m_vm.propertyNames->from), "Expected 'from' before exported module name");
next();
auto moduleName = parseModuleName(context);
failIfFalse(moduleName, "Cannot parse the 'from' clause");
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted export declaration");
if (exportedName) {
semanticFailIfFalse(exportName(*exportedName), "Cannot export a duplicate name '", exportedName->impl(), "'");
auto specifierList = context.createExportSpecifierList();
auto localName = &m_vm.propertyNames->starNamespacePrivateName;
auto specifier = context.createExportSpecifier(specifierLocation, *localName, *exportedName);
context.appendExportSpecifier(specifierList, specifier);
return context.createExportNamedDeclaration(exportLocation, specifierList, moduleName);
}
return context.createExportAllDeclaration(exportLocation, moduleName);
}
case DEFAULT: {
// export default HoistableDeclaration[~Yield, ~Await, +Default]
// export default ClassDeclaration[~Yield, ~Await, +Default]
// export default [lookahead not-in { function, async [no LineTerminator here] function, class }] AssignmentExpression[+In, ~Yield, ~Await]
next();
TreeStatement result = 0;
bool isFunctionOrClassDeclaration = false;
const Identifier* localName = nullptr;
bool startsWithFunction = match(FUNCTION);
if (startsWithFunction || match(CLASSTOKEN)) {
SavePoint savePoint = createSavePoint(context);
isFunctionOrClassDeclaration = true;
next();
// ES6 Generators
if (startsWithFunction && match(TIMES))
next();
if (match(IDENT))
localName = m_token.m_data.ident;
restoreSavePoint(context, savePoint);
} else if (matchContextualKeyword(m_vm.propertyNames->async)) {
// export default async function xxx() { }
// export default async function * yyy() { }
SavePoint savePoint = createSavePoint(context);
next();
if (match(FUNCTION) && !m_lexer->hasLineTerminatorBeforeToken()) {
next();
// Async Generators
if (match(TIMES))
next();
if (match(IDENT))
localName = m_token.m_data.ident;
isFunctionOrClassDeclaration = true;
}
restoreSavePoint(context, savePoint);
}
if (!localName)
localName = &m_vm.propertyNames->starDefaultPrivateName;
if (isFunctionOrClassDeclaration) {
if (startsWithFunction) {
ASSERT(match(FUNCTION));
DepthManager statementDepth(&m_statementDepth);
m_statementDepth = 1;
result = parseFunctionDeclaration(context, FunctionDeclarationType::Declaration, ExportType::NotExported, DeclarationDefaultContext::ExportDefault);
} else if (match(CLASSTOKEN)) {
result = parseClassDeclaration(context, ExportType::NotExported, DeclarationDefaultContext::ExportDefault);
} else {
ASSERT(matchContextualKeyword(m_vm.propertyNames->async));
next();
DepthManager statementDepth(&m_statementDepth);
m_statementDepth = 1;
result = parseAsyncFunctionDeclaration(context, ExportType::NotExported, DeclarationDefaultContext::ExportDefault);
}
} else {
// export default expr;
//
// It should be treated as the same to the following.
//
// const *default* = expr;
// export { *default* as default }
//
// In the above example, *default* is the invisible variable to the users.
// We use the private symbol to represent the name of this variable.
JSTokenLocation location(tokenLocation());
JSTextPosition start = tokenStartPosition();
TreeExpression expression = parseAssignmentExpression(context);
failIfFalse(expression, "Cannot parse expression");
DeclarationResultMask declarationResult = declareVariable(&m_vm.propertyNames->starDefaultPrivateName, DeclarationType::ConstDeclaration);
if (declarationResult & DeclarationResult::InvalidDuplicateDeclaration)
internalFailWithMessage(false, "Only one 'default' export is allowed");
TreeExpression assignment = context.createAssignResolve(location, m_vm.propertyNames->starDefaultPrivateName, expression, start, start, tokenEndPosition(), AssignmentContext::ConstDeclarationStatement);
result = context.createExprStatement(location, assignment, start, tokenEndPosition());
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted export declaration");
}
failIfFalse(result, "Cannot parse the declaration");
semanticFailIfFalse(exportName(m_vm.propertyNames->defaultKeyword), "Only one 'default' export is allowed");
m_moduleScopeData->exportBinding(*localName, m_vm.propertyNames->defaultKeyword);
return context.createExportDefaultDeclaration(exportLocation, result, *localName);
}
case OPENBRACE: {
// export ExportClause FromClause ;
// export ExportClause ;
//
// ExportClause :
// { }
// { ExportsList }
// { ExportsList , }
//
// ExportsList :
// ExportSpecifier
// ExportsList , ExportSpecifier
next();
auto specifierList = context.createExportSpecifierList();
Vector<std::pair<const Identifier*, const Identifier*>> maybeExportedLocalNames;
bool hasKeywordForLocalBindings = false;
bool hasReferencedModuleExportNames = false;
while (!match(CLOSEBRACE)) {
failIfFalse(matchIdentifierOrKeyword() || match(STRING), "Expected a variable name or a module export name string for the export declaration");
auto specifier = parseExportSpecifier(context, maybeExportedLocalNames, hasKeywordForLocalBindings, hasReferencedModuleExportNames);
failIfFalse(specifier, "Cannot parse the named export");
context.appendExportSpecifier(specifierList, specifier);
if (!consume(COMMA))
break;
}
handleProductionOrFail2(CLOSEBRACE, "}", "end", "export list");
typename TreeBuilder::ModuleName moduleName = 0;
if (matchContextualKeyword(m_vm.propertyNames->from)) {
next();
moduleName = parseModuleName(context);
failIfFalse(moduleName, "Cannot parse the 'from' clause");
} else
semanticFailIfTrue(hasReferencedModuleExportNames, "Cannot use module export names if they reference variable names in the current module");
failIfFalse(autoSemiColon(), "Expected a ';' following a targeted export declaration");
if (!moduleName) {
semanticFailIfTrue(hasKeywordForLocalBindings, "Cannot use keyword as exported variable name");
// Since this export declaration does not have module specifier part, it exports the local bindings.
// While the export declaration with module specifier does not have any effect on the current module's scope,
// the export named declaration without module specifier references the local binding names.
// For example,
// export { A, B, C as D } from "mod"
// does not have effect on the current module's scope. But,
// export { A, B, C as D }
// will reference the current module's bindings.
for (const auto& pair : maybeExportedLocalNames) {
const Identifier* localName = pair.first;
const Identifier* exportedName = pair.second;
m_moduleScopeData->exportBinding(*localName, *exportedName);
}
}
return context.createExportNamedDeclaration(exportLocation, specifierList, moduleName);
}
default: {
// export VariableStatement
// export Declaration
TreeStatement result = 0;
switch (m_token.m_type) {
case VAR:
result = parseVariableDeclaration(context, DeclarationType::VarDeclaration, ExportType::Exported);
break;
case CONSTTOKEN:
result = parseVariableDeclaration(context, DeclarationType::ConstDeclaration, ExportType::Exported);
break;
case LET:
result = parseVariableDeclaration(context, DeclarationType::LetDeclaration, ExportType::Exported);
break;
case FUNCTION: {
DepthManager statementDepth(&m_statementDepth);
m_statementDepth = 1;
result = parseFunctionDeclaration(context, FunctionDeclarationType::Declaration, ExportType::Exported);
break;
}
case CLASSTOKEN:
result = parseClassDeclaration(context, ExportType::Exported);
break;
case IDENT:
if (*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped) {
next();
semanticFailIfFalse(match(FUNCTION) && !m_lexer->hasLineTerminatorBeforeToken(), "Expected 'function' keyword following 'async' keyword with no preceding line terminator");
DepthManager statementDepth(&m_statementDepth);
m_statementDepth = 1;
result = parseAsyncFunctionDeclaration(context, ExportType::Exported);
break;
}
FALLTHROUGH;
default:
failWithMessage("Expected either a declaration or a variable statement");
break;
}
failIfFalse(result, "Cannot parse the declaration");
return context.createExportLocalDeclaration(exportLocation, result);
}
}
RELEASE_ASSERT_NOT_REACHED();
return 0;
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseExpression(TreeBuilder& context, IsOnlyChildOfStatement isStatement)
{
failIfStackOverflow();
JSTokenLocation headLocation(tokenLocation());
TreeExpression node = parseAssignmentExpression(context);
failIfFalse(node, "Cannot parse expression");
context.setEndOffset(node, m_lastTokenEndPosition.offset);
if (!match(COMMA))
return node;
next();
m_parserState.nonTrivialExpressionCount++;
m_parserState.nonLHSCount++;
JSTokenLocation tailLocation(tokenLocation());
TreeExpression right = parseAssignmentExpression(context);
failIfFalse(right, "Cannot parse expression in a comma expression");
context.setEndOffset(right, m_lastTokenEndPosition.offset);
typename TreeBuilder::Comma head = context.createCommaExpr(headLocation, node);
if (isStatement == IsOnlyChildOfStatement::Yes)
recordPauseLocation(context.breakpointLocation(head));
typename TreeBuilder::Comma tail = context.appendToCommaExpr(tailLocation, head, head, right);
if (isStatement == IsOnlyChildOfStatement::Yes)
recordPauseLocation(context.breakpointLocation(tail));
while (match(COMMA)) {
next(TreeBuilder::DontBuildStrings);
tailLocation = tokenLocation();
right = parseAssignmentExpression(context);
failIfFalse(right, "Cannot parse expression in a comma expression");
context.setEndOffset(right, m_lastTokenEndPosition.offset);
tail = context.appendToCommaExpr(tailLocation, head, tail, right);
if (isStatement == IsOnlyChildOfStatement::Yes)
recordPauseLocation(context.breakpointLocation(tail));
}
context.setEndOffset(head, m_lastTokenEndPosition.offset);
return head;
}
template <typename LexerType>
template <typename TreeBuilder> TreeExpression Parser<LexerType>::parseAssignmentExpressionOrPropagateErrorClass(TreeBuilder& context)
{
ExpressionErrorClassifier classifier(this);
auto assignment = parseAssignmentExpression(context, classifier);
if (!assignment)
classifier.propagateExpressionErrorClass();
return assignment;
}
template <typename LexerType>
template <typename TreeBuilder> TreeExpression Parser<LexerType>::parseAssignmentExpression(TreeBuilder& context)
{
ExpressionErrorClassifier classifier(this);
return parseAssignmentExpression(context, classifier);
}
template <typename LexerType>
template <typename TreeBuilder> NEVER_INLINE const char* Parser<LexerType>::metaPropertyName(TreeBuilder& context, TreeExpression expr)
{
if (context.isNewTarget(expr))
return "new.target";
if (context.isImportMeta(expr))
return "import.meta";
RELEASE_ASSERT_NOT_REACHED();
return "error";
}
template <typename LexerType>
template <typename TreeBuilder> bool Parser<LexerType>::isSimpleAssignmentTarget(TreeBuilder& context, TreeExpression expr)
{
// Web compatibility concerns prevent us from handling a function call LHS as an early error in sloppy mode.
// This behavior is currently unspecified, but see: https://github.com/tc39/ecma262/issues/257#issuecomment-195106880
return context.isLocation(expr) || (!strictMode() && context.isFunctionCall(expr));
}
template <typename LexerType>
template <typename TreeBuilder> TreeExpression Parser<LexerType>::parseAssignmentExpression(TreeBuilder& context, ExpressionErrorClassifier& classifier)
{
ASSERT(!hasError());
failIfStackOverflow();
if (match(YIELD) && !isYIELDMaskedAsIDENT(currentScope()->isGenerator()))
return parseYieldExpression(context);
JSTextPosition start = tokenStartPosition();
JSTokenLocation location(tokenLocation());
int initialAssignmentCount = m_parserState.assignmentCount;
int initialNonLHSCount = m_parserState.nonLHSCount;
bool maybeAssignmentPattern = match(OPENBRACE) || match(OPENBRACKET);
bool wasOpenParen = match(OPENPAREN);
// Do not use matchSpecIdentifier() here since it is slower than isIdentifierOrKeyword.
// Whether spec identifier is will be validated by isArrowFunctionParameters().
bool wasIdentifierOrKeyword = isIdentifierOrKeyword(m_token);
bool maybeValidArrowFunctionStart = wasOpenParen || wasIdentifierOrKeyword;
SavePoint savePoint = createSavePoint(context);
size_t usedVariablesSize = 0;
if (wasOpenParen) {
usedVariablesSize = currentScope()->currentUsedVariablesSize();
currentScope()->pushUsedVariableSet();
}
TreeExpression lhs = parseConditionalExpression(context);
if (maybeValidArrowFunctionStart && !match(EOFTOK)) {
bool isArrowFunctionToken = match(ARROWFUNCTION);
if (!lhs || isArrowFunctionToken) {
SavePointWithError errorRestorationSavePoint = swapSavePointForError(context, savePoint);
bool isAsyncArrow = false;
if (UNLIKELY(classifier.indicatesPossibleAsyncArrowFunction())) {
if (matchContextualKeyword(m_vm.propertyNames->async)) {
next();
isAsyncArrow = !m_lexer->hasLineTerminatorBeforeToken();
}
}
if (isArrowFunctionParameters(context)) {
if (wasOpenParen)
currentScope()->revertToPreviousUsedVariables(usedVariablesSize);
return parseArrowFunctionExpression(context, isAsyncArrow);
}
if (isArrowFunctionToken)
propagateError();
restoreSavePointWithError(context, errorRestorationSavePoint);
if (isArrowFunctionToken)
failDueToUnexpectedToken();
}
}
if (!lhs && (!maybeAssignmentPattern || !classifier.indicatesPossiblePattern()))
propagateError();
if (maybeAssignmentPattern && (!lhs || (context.isObjectOrArrayLiteral(lhs) && match(EQUAL)))) {
SavePointWithError expressionErrorLocation = swapSavePointForError(context, savePoint);
auto pattern = tryParseDestructuringPatternExpression(context, AssignmentContext::AssignmentExpression);
if (classifier.indicatesPossiblePattern() && (!pattern || !match(EQUAL))) {
restoreSavePointWithError(context, expressionErrorLocation);
return 0;
}
failIfFalse(pattern, "Cannot parse assignment pattern");
consumeOrFail(EQUAL, "Expected '=' following assignment pattern");
auto rhs = parseAssignmentExpression(context);
if (!rhs)
propagateError();
return context.createDestructuringAssignment(location, pattern, rhs);
}
failIfFalse(lhs, "Cannot parse expression");
if (initialNonLHSCount != m_parserState.nonLHSCount) {
if (m_token.m_type >= EQUAL && m_token.m_type <= ANDEQUAL)
semanticFail("Left hand side of operator '", getToken(), "' must be a reference");
return lhs;
}
int assignmentStack = 0;
Operator op;
bool hadAssignment = false;
while (true) {
switch (m_token.m_type) {
case EQUAL: op = Operator::Equal; break;
case PLUSEQUAL: op = Operator::PlusEq; break;
case MINUSEQUAL: op = Operator::MinusEq; break;
case MULTEQUAL: op = Operator::MultEq; break;
case DIVEQUAL: op = Operator::DivEq; break;
case LSHIFTEQUAL: op = Operator::LShift; break;
case RSHIFTEQUAL: op = Operator::RShift; break;
case URSHIFTEQUAL: op = Operator::URShift; break;
case BITANDEQUAL: op = Operator::BitAndEq; break;
case BITXOREQUAL: op = Operator::BitXOrEq; break;
case BITOREQUAL: op = Operator::BitOrEq; break;
case MODEQUAL: op = Operator::ModEq; break;
case POWEQUAL: op = Operator::PowEq; break;
case COALESCEEQUAL: op = Operator::CoalesceEq; break;
case OREQUAL: op = Operator::OrEq; break;
case ANDEQUAL: op = Operator::AndEq; break;
default:
goto end;
}
m_parserState.nonTrivialExpressionCount++;
hadAssignment = true;
semanticFailIfTrue(context.isMetaProperty(lhs), metaPropertyName(context, lhs), " can't be the left hand side of an assignment expression");
semanticFailIfFalse(isSimpleAssignmentTarget(context, lhs), "Left side of assignment is not a reference");
context.assignmentStackAppend(assignmentStack, lhs, start, tokenStartPosition(), m_parserState.assignmentCount, op);
start = tokenStartPosition();
m_parserState.assignmentCount++;
next(TreeBuilder::DontBuildStrings);
if (strictMode() && m_parserState.lastIdentifier && context.isResolve(lhs)) {
failIfTrueIfStrict(m_vm.propertyNames->eval == *m_parserState.lastIdentifier, "Cannot modify 'eval' in strict mode");
failIfTrueIfStrict(m_vm.propertyNames->arguments == *m_parserState.lastIdentifier, "Cannot modify 'arguments' in strict mode");
m_parserState.lastIdentifier = nullptr;
}
lhs = parseAssignmentExpression(context);
failIfFalse(lhs, "Cannot parse the right hand side of an assignment expression");
if (initialNonLHSCount != m_parserState.nonLHSCount) {
if (m_token.m_type >= EQUAL && m_token.m_type <= ANDEQUAL)
semanticFail("Left hand side of operator '", getToken(), "' must be a reference");
break;
}
}
end:
if (hadAssignment)
m_parserState.nonLHSCount++;
while (assignmentStack)
lhs = context.createAssignment(location, assignmentStack, lhs, initialAssignmentCount, m_parserState.assignmentCount, lastTokenEndPosition());
return lhs;
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseYieldExpression(TreeBuilder& context)
{
// YieldExpression[In] :
// yield
// yield [no LineTerminator here] AssignmentExpression[?In, Yield]
// yield [no LineTerminator here] * AssignmentExpression[?In, Yield]
// http://ecma-international.org/ecma-262/6.0/#sec-generator-function-definitions
failIfFalse(currentScope()->isGenerator() && !currentScope()->isArrowFunctionBoundary(), "Cannot use yield expression out of generator");
// http://ecma-international.org/ecma-262/6.0/#sec-generator-function-definitions-static-semantics-early-errors
failIfTrue(m_parserState.functionParsePhase == FunctionParsePhase::Parameters, "Cannot use yield expression within parameters");
JSTokenLocation location(tokenLocation());
JSTextPosition divotStart = tokenStartPosition();
ASSERT(match(YIELD));
SavePoint savePoint = createSavePoint(context);
next();
if (m_lexer->hasLineTerminatorBeforeToken())
return context.createYield(location);
bool delegate = consume(TIMES);
JSTextPosition argumentStart = tokenStartPosition();
TreeExpression argument = parseAssignmentExpression(context);
if (!argument) {
restoreSavePoint(context, savePoint);
next();
return context.createYield(location);
}
return context.createYield(location, argument, delegate, divotStart, argumentStart, lastTokenEndPosition());
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseAwaitExpression(TreeBuilder& context)
{
ASSERT(match(AWAIT));
ASSERT(currentScope()->isAsyncFunction());
ASSERT(m_parserState.functionParsePhase != FunctionParsePhase::Parameters);
JSTokenLocation location(tokenLocation());
JSTextPosition divotStart = tokenStartPosition();
next();
JSTextPosition argumentStart = tokenStartPosition();
ExpressionErrorClassifier classifier(this);
TreeExpression argument = parseUnaryExpression(context);
failIfFalse(argument, "Failed to parse await expression");
return context.createAwait(location, argument, divotStart, argumentStart, lastTokenEndPosition());
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseConditionalExpression(TreeBuilder& context)
{
JSTokenLocation location(tokenLocation());
TreeExpression cond = parseBinaryExpression(context);
failIfFalse(cond, "Cannot parse expression");
if (!match(QUESTION))
return cond;
m_parserState.nonTrivialExpressionCount++;
m_parserState.nonLHSCount++;
next(TreeBuilder::DontBuildStrings);
TreeExpression lhs = 0;
{
// this block is necessary so that we don't leave `in` enabled for the rhs
AllowInOverride allowInOverride(this);
lhs = parseAssignmentExpression(context);
}
failIfFalse(lhs, "Cannot parse left hand side of ternary operator");
context.setEndOffset(lhs, m_lastTokenEndPosition.offset);
consumeOrFailWithFlags(COLON, TreeBuilder::DontBuildStrings, "Expected ':' in ternary operator");
TreeExpression rhs = parseAssignmentExpression(context);
failIfFalse(rhs, "Cannot parse right hand side of ternary operator");
context.setEndOffset(rhs, m_lastTokenEndPosition.offset);
return context.createConditionalExpr(location, cond, lhs, rhs);
}
ALWAYS_INLINE static bool isUnaryOpExcludingUpdateOp(JSTokenType token)
{
if (isUpdateOp(token))
return false;
return isUnaryOp(token);
}
template <typename LexerType>
int Parser<LexerType>::isBinaryOperator(JSTokenType token)
{
if (m_allowsIn)
return token & (BinaryOpTokenPrecedenceMask << BinaryOpTokenAllowsInPrecedenceAdditionalShift);
return token & BinaryOpTokenPrecedenceMask;
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseBinaryExpression(TreeBuilder& context)
{
int operandStackDepth = 0;
int operatorStackDepth = 0;
typename TreeBuilder::BinaryExprContext binaryExprContext(context);
JSTokenLocation location(tokenLocation());
bool hasLogicalOperator = false;
bool hasCoalesceOperator = false;
while (true) {
JSTextPosition exprStart = tokenStartPosition();
int initialAssignments = m_parserState.assignmentCount;
JSTokenType leadingTokenTypeForUnaryExpression = m_token.m_type;
TreeExpression current = parseUnaryExpression(context);
failIfFalse(current, "Cannot parse expression");
context.appendBinaryExpressionInfo(operandStackDepth, current, exprStart, lastTokenEndPosition(), lastTokenEndPosition(), initialAssignments != m_parserState.assignmentCount);
int precedence = isBinaryOperator(m_token.m_type);
if (!precedence)
break;
// 12.6 https://tc39.github.io/ecma262/#sec-exp-operator
// ExponentiationExpresion is described as follows.
//
// ExponentiationExpression[Yield]:
// UnaryExpression[?Yield]
// UpdateExpression[?Yield] ** ExponentiationExpression[?Yield]
//
// As we can see, the left hand side of the ExponentiationExpression is UpdateExpression, not UnaryExpression.
// So placing UnaryExpression not included in UpdateExpression here is a syntax error.
// This is intentional. For example, if UnaryExpression is allowed, we can have the code like `-x**y`.
// But this is confusing: `-(x**y)` OR `(-x)**y`, which interpretation is correct?
// To avoid this problem, ECMA262 makes unparenthesized exponentiation expression as operand of unary operators an early error.
// More rationale: https://mail.mozilla.org/pipermail/es-discuss/2015-September/044232.html
//
// Here, we guarantee that the left hand side of this expression is not unary expression by checking the leading operator of the parseUnaryExpression.
// This check just works. Let's consider the example,
// y <> -x ** z
// ^
// Check this.
// If the binary operator <> has higher precedence than one of "**", this check does not work.
// But it's OK for ** because the operator "**" has the highest operator precedence in the binary operators.
failIfTrue(match(POW) && isUnaryOpExcludingUpdateOp(leadingTokenTypeForUnaryExpression), "Ambiguous unary expression in the left hand side of the exponentiation expression; parentheses must be used to disambiguate the expression");
// Mixing ?? with || or && is currently specified as an early error.
// Since ?? is the lowest-precedence binary operator, it suffices to check whether these ever coexist in the operator stack.
if (match(AND) || match(OR))
hasLogicalOperator = true;
else if (match(COALESCE))
hasCoalesceOperator = true;
failIfTrue(hasLogicalOperator && hasCoalesceOperator, "Coalescing and logical operators used together in the same expression; parentheses must be used to disambiguate");
m_parserState.nonTrivialExpressionCount++;
m_parserState.nonLHSCount++;
int operatorToken = m_token.m_type;
next(TreeBuilder::DontBuildStrings);
while (operatorStackDepth && context.operatorStackShouldReduce(precedence)) {
ASSERT(operandStackDepth > 1);
typename TreeBuilder::BinaryOperand rhs = context.getFromOperandStack(-1);
typename TreeBuilder::BinaryOperand lhs = context.getFromOperandStack(-2);
context.shrinkOperandStackBy(operandStackDepth, 2);
context.appendBinaryOperation(location, operandStackDepth, operatorStackDepth, lhs, rhs);
context.operatorStackPop(operatorStackDepth);
}
context.operatorStackAppend(operatorStackDepth, operatorToken, precedence);
}
while (operatorStackDepth) {
ASSERT(operandStackDepth > 1);
typename TreeBuilder::BinaryOperand rhs = context.getFromOperandStack(-1);
typename TreeBuilder::BinaryOperand lhs = context.getFromOperandStack(-2);
context.shrinkOperandStackBy(operandStackDepth, 2);
context.appendBinaryOperation(location, operandStackDepth, operatorStackDepth, lhs, rhs);
context.operatorStackPop(operatorStackDepth);
}
return context.popOperandStack(operandStackDepth);
}
template <typename LexerType>
template <class TreeBuilder> TreeProperty Parser<LexerType>::parseProperty(TreeBuilder& context)
{
SourceParseMode parseMode = SourceParseMode::MethodMode;
bool wasIdent = false;
if (consume(TIMES))
parseMode = SourceParseMode::GeneratorWrapperMethodMode;
parseProperty:
switch (m_token.m_type) {
case ESCAPED_KEYWORD:
case IDENT:
if (UNLIKELY(*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped)) {
if (parseMode == SourceParseMode::MethodMode) {
SavePoint savePoint = createSavePoint(context);
next();
if (match(COLON) || match(OPENPAREN) || match(COMMA) || match(CLOSEBRACE)) {
restoreSavePoint(context, savePoint);
wasIdent = true;
goto namedProperty;
}
failIfTrue(m_lexer->hasLineTerminatorBeforeToken(), "Expected a property name following keyword 'async'");
if (UNLIKELY(consume(TIMES)))
parseMode = SourceParseMode::AsyncGeneratorWrapperMethodMode;
else
parseMode = SourceParseMode::AsyncMethodMode;
goto parseProperty;
}
}
FALLTHROUGH;
case YIELD:
case AWAIT:
wasIdent = true;
FALLTHROUGH;
case STRING: {
namedProperty:
const Identifier* ident = m_token.m_data.ident;
bool escaped = m_token.m_data.escaped;
unsigned getterOrSetterStartOffset = tokenStart();
JSToken identToken = m_token;
if (wasIdent && !isGeneratorMethodParseMode(parseMode) && (!escaped && (*ident == m_vm.propertyNames->get || *ident == m_vm.propertyNames->set)))
nextExpectIdentifier(LexerFlags::IgnoreReservedWords);
else
nextExpectIdentifier(TreeBuilder::DontBuildKeywords | LexerFlags::IgnoreReservedWords);
if (!isGeneratorMethodParseMode(parseMode) && !isAsyncMethodParseMode(parseMode) && match(COLON)) {
next();
TreeExpression node = parseAssignmentExpressionOrPropagateErrorClass(context);
failIfFalse(node, "Cannot parse expression for property declaration");
context.setEndOffset(node, m_lexer->currentOffset());
InferName inferName = ident && *ident == m_vm.propertyNames->underscoreProto ? InferName::Disallowed : InferName::Allowed;
return context.createProperty(ident, node, PropertyNode::Constant, SuperBinding::NotNeeded, inferName, ClassElementTag::No);
}
if (match(OPENPAREN)) {
auto method = parsePropertyMethod(context, ident, parseMode);
propagateError();
return context.createProperty(ident, method, PropertyNode::Constant, SuperBinding::Needed, InferName::Allowed, ClassElementTag::No);
}
failIfTrue(parseMode != SourceParseMode::MethodMode, "Expected a parenthesis for argument list");
failIfFalse(wasIdent, "Expected an identifier as property name");
if (match(COMMA) || match(CLOSEBRACE)) {
semanticFailureDueToKeywordCheckingToken(identToken, "shorthand property name");
JSTextPosition start = tokenStartPosition();
JSTokenLocation location(tokenLocation());
currentScope()->useVariable(ident, m_vm.propertyNames->eval == *ident);
if (currentScope()->isArrowFunction())
currentScope()->setInnerArrowFunctionUsesEval();
TreeExpression node = context.createResolve(location, *ident, start, lastTokenEndPosition());
return context.createProperty(ident, node, static_cast<PropertyNode::Type>(PropertyNode::Constant | PropertyNode::Shorthand), SuperBinding::NotNeeded, InferName::Allowed, ClassElementTag::No);
}
if (match(EQUAL)) // CoverInitializedName is exclusive to BindingPattern and AssignmentPattern
classifyExpressionError(ErrorIndicatesPattern);
Optional<PropertyNode::Type> type;
if (!escaped) {
if (*ident == m_vm.propertyNames->get)
type = PropertyNode::Getter;
else if (*ident == m_vm.propertyNames->set)
type = PropertyNode::Setter;
}
if (!type)
failWithMessage("Expected a ':' following the property name '", ident->impl(), "'");
return parseGetterSetter(context, type.value(), getterOrSetterStartOffset, ConstructorKind::None, ClassElementTag::No);
}
case DOUBLE:
case INTEGER: {
double propertyName = m_token.m_data.doubleValue;
next();
if (match(OPENPAREN)) {
const Identifier& ident = m_parserArena.identifierArena().makeNumericIdentifier(const_cast<VM&>(m_vm), propertyName);
auto method = parsePropertyMethod(context, &ident, parseMode);
propagateError();
return context.createProperty(&ident, method, PropertyNode::Constant, SuperBinding::Needed, InferName::Allowed, ClassElementTag::No);
}
failIfTrue(parseMode != SourceParseMode::MethodMode, "Expected a parenthesis for argument list");
consumeOrFail(COLON, "Expected ':' after property name");
TreeExpression node = parseAssignmentExpression(context);
failIfFalse(node, "Cannot parse expression for property declaration");
context.setEndOffset(node, m_lexer->currentOffset());
return context.createProperty(const_cast<VM&>(m_vm), m_parserArena, propertyName, node, PropertyNode::Constant, SuperBinding::NotNeeded, ClassElementTag::No);
}
case BIGINT: {
const Identifier* ident = &m_parserArena.identifierArena().makeBigIntDecimalIdentifier(const_cast<VM&>(m_vm), *m_token.m_data.bigIntString, m_token.m_data.radix);
next();
if (match(OPENPAREN)) {
auto method = parsePropertyMethod(context, ident, parseMode);
propagateError();
return context.createProperty(ident, method, PropertyNode::Constant, SuperBinding::Needed, InferName::Allowed, ClassElementTag::No);
}
failIfTrue(parseMode != SourceParseMode::MethodMode, "Expected a parenthesis for argument list");
consumeOrFail(COLON, "Expected ':' after property name");
TreeExpression node = parseAssignmentExpression(context);
failIfFalse(node, "Cannot parse expression for property declaration");
context.setEndOffset(node, m_lexer->currentOffset());
return context.createProperty(ident, node, PropertyNode::Constant, SuperBinding::NotNeeded, InferName::Allowed, ClassElementTag::No);
}
case OPENBRACKET: {
next();
auto propertyName = parseAssignmentExpression(context);
failIfFalse(propertyName, "Cannot parse computed property name");
handleProductionOrFail(CLOSEBRACKET, "]", "end", "computed property name");
if (match(OPENPAREN)) {
auto method = parsePropertyMethod(context, &m_vm.propertyNames->nullIdentifier, parseMode);
propagateError();
return context.createProperty(propertyName, method, static_cast<PropertyNode::Type>(PropertyNode::Constant | PropertyNode::Computed), SuperBinding::Needed, ClassElementTag::No);
}
failIfTrue(parseMode != SourceParseMode::MethodMode, "Expected a parenthesis for argument list");
consumeOrFail(COLON, "Expected ':' after property name");
TreeExpression node = parseAssignmentExpression(context);
failIfFalse(node, "Cannot parse expression for property declaration");
context.setEndOffset(node, m_lexer->currentOffset());
return context.createProperty(propertyName, node, static_cast<PropertyNode::Type>(PropertyNode::Constant | PropertyNode::Computed), SuperBinding::NotNeeded, ClassElementTag::No);
}
case DOTDOTDOT: {
auto spreadLocation = m_token.m_location;
auto start = m_token.m_startPosition;
auto divot = m_token.m_endPosition;
next();
TreeExpression elem = parseAssignmentExpressionOrPropagateErrorClass(context);
failIfFalse(elem, "Cannot parse subject of a spread operation");
auto node = context.createObjectSpreadExpression(spreadLocation, elem, start, divot, m_lastTokenEndPosition);
return context.createProperty(node, PropertyNode::Spread, SuperBinding::NotNeeded, ClassElementTag::No);
}
default:
failIfFalse(m_token.m_type & KeywordTokenFlag, "Expected a property name");
wasIdent = true; // Treat keyword token as an identifier
goto namedProperty;
}
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parsePropertyMethod(TreeBuilder& context, const Identifier* methodName, SourceParseMode parseMode)
{
ASSERT(isMethodParseMode(parseMode));
JSTokenLocation methodLocation(tokenLocation());
unsigned methodStart = tokenStart();
ParserFunctionInfo<TreeBuilder> methodInfo;
methodInfo.name = methodName;
failIfFalse((parseFunctionInfo(context, FunctionNameRequirements::Unnamed, parseMode, false, ConstructorKind::None, SuperBinding::Needed, methodStart, methodInfo, FunctionDefinitionType::Method)), "Cannot parse this method");
return context.createMethodDefinition(methodLocation, methodInfo);
}
template <typename LexerType>
template <class TreeBuilder> TreeProperty Parser<LexerType>::parseGetterSetter(TreeBuilder& context, PropertyNode::Type type, unsigned getterOrSetterStartOffset,
ConstructorKind constructorKind, ClassElementTag tag)
{
const Identifier* stringPropertyName = nullptr;
double numericPropertyName = 0;
TreeExpression computedPropertyName = 0;
JSTokenLocation location(tokenLocation());
if (matchSpecIdentifier() || match(STRING) || m_token.m_type & KeywordTokenFlag) {
stringPropertyName = m_token.m_data.ident;
semanticFailIfTrue(tag == ClassElementTag::Static && *stringPropertyName == m_vm.propertyNames->prototype,
"Cannot declare a static method named 'prototype'");
semanticFailIfTrue(tag == ClassElementTag::Instance && *stringPropertyName == m_vm.propertyNames->constructor,
"Cannot declare a getter or setter named 'constructor'");
next();
} else if (match(DOUBLE) || match(INTEGER)) {
numericPropertyName = m_token.m_data.doubleValue;
next();
} else if (match(BIGINT)) {
stringPropertyName = &m_parserArena.identifierArena().makeBigIntDecimalIdentifier(const_cast<VM&>(m_vm), *m_token.m_data.bigIntString, m_token.m_data.radix);
next();
} else if (match(OPENBRACKET)) {
next();
computedPropertyName = parseAssignmentExpression(context);
failIfFalse(computedPropertyName, "Cannot parse computed property name");
handleProductionOrFail(CLOSEBRACKET, "]", "end", "computed property name");
} else
failDueToUnexpectedToken();
ParserFunctionInfo<TreeBuilder> info;
if (type & PropertyNode::Getter) {
failIfFalse(match(OPENPAREN), "Expected a parameter list for getter definition");
failIfFalse((parseFunctionInfo(context, FunctionNameRequirements::Unnamed, SourceParseMode::GetterMode, false, constructorKind, SuperBinding::Needed, getterOrSetterStartOffset, info, FunctionDefinitionType::Method)), "Cannot parse getter definition");
} else {
failIfFalse(match(OPENPAREN), "Expected a parameter list for setter definition");
failIfFalse((parseFunctionInfo(context, FunctionNameRequirements::Unnamed, SourceParseMode::SetterMode, false, constructorKind, SuperBinding::Needed, getterOrSetterStartOffset, info, FunctionDefinitionType::Method)), "Cannot parse setter definition");
}
if (stringPropertyName)
return context.createGetterOrSetterProperty(location, type, stringPropertyName, info, tag);
if (computedPropertyName)
return context.createGetterOrSetterProperty(location, static_cast<PropertyNode::Type>(type | PropertyNode::Computed), computedPropertyName, info, tag);
return context.createGetterOrSetterProperty(const_cast<VM&>(m_vm), m_parserArena, location, type, numericPropertyName, info, tag);
}
template <typename LexerType>
void Parser<LexerType>::recordPauseLocation(const JSTextPosition& position)
{
if (LIKELY(!m_debuggerParseData))
return;
if (position.line < 0)
return;
m_debuggerParseData->pausePositions.appendPause(position);
}
template <typename LexerType>
void Parser<LexerType>::recordFunctionEntryLocation(const JSTextPosition& position)
{
if (LIKELY(!m_debuggerParseData))
return;
m_debuggerParseData->pausePositions.appendEntry(position);
}
template <typename LexerType>
void Parser<LexerType>::recordFunctionLeaveLocation(const JSTextPosition& position)
{
if (LIKELY(!m_debuggerParseData))
return;
m_debuggerParseData->pausePositions.appendLeave(position);
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseObjectLiteral(TreeBuilder& context)
{
consumeOrFail(OPENBRACE, "Expected opening '{' at the start of an object literal");
int oldNonLHSCount = m_parserState.nonLHSCount;
JSTokenLocation location(tokenLocation());
if (match(CLOSEBRACE)) {
next();
return context.createObjectLiteral(location);
}
TreeProperty property = parseProperty(context);
failIfFalse(property, "Cannot parse object literal property");
bool seenProtoSetter = context.isUnderscoreProtoSetter(property);
TreePropertyList propertyList = context.createPropertyList(location, property);
TreePropertyList tail = propertyList;
while (match(COMMA)) {
next();
if (match(CLOSEBRACE))
break;
JSTokenLocation propertyLocation(tokenLocation());
property = parseProperty(context);
failIfFalse(property, "Cannot parse object literal property");
if (context.isUnderscoreProtoSetter(property)) {
// https://tc39.es/ecma262/#sec-__proto__-property-names-in-object-initializers
semanticFailIfTrue(seenProtoSetter, "Attempted to redefine __proto__ property");
seenProtoSetter = true;
}
tail = context.createPropertyList(propertyLocation, property, tail);
}
location = tokenLocation();
handleProductionOrFail2(CLOSEBRACE, "}", "end", "object literal");
m_parserState.nonLHSCount = oldNonLHSCount;
return context.createObjectLiteral(location, propertyList);
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseArrayLiteral(TreeBuilder& context)
{
consumeOrFailWithFlags(OPENBRACKET, TreeBuilder::DontBuildStrings, "Expected an opening '[' at the beginning of an array literal");
int oldNonLHSCount = m_parserState.nonLHSCount;
int elisions = 0;
while (match(COMMA)) {
next(TreeBuilder::DontBuildStrings);
elisions++;
}
if (match(CLOSEBRACKET)) {
JSTokenLocation location(tokenLocation());
next(TreeBuilder::DontBuildStrings);
return context.createArray(location, elisions);
}
TreeExpression elem;
if (UNLIKELY(match(DOTDOTDOT))) {
auto spreadLocation = m_token.m_location;
auto start = m_token.m_startPosition;
auto divot = m_token.m_endPosition;
next();
auto spreadExpr = parseAssignmentExpressionOrPropagateErrorClass(context);
failIfFalse(spreadExpr, "Cannot parse subject of a spread operation");
elem = context.createSpreadExpression(spreadLocation, spreadExpr, start, divot, m_lastTokenEndPosition);
} else
elem = parseAssignmentExpressionOrPropagateErrorClass(context);
failIfFalse(elem, "Cannot parse array literal element");
typename TreeBuilder::ElementList elementList = context.createElementList(elisions, elem);
typename TreeBuilder::ElementList tail = elementList;
elisions = 0;
while (match(COMMA)) {
next(TreeBuilder::DontBuildStrings);
elisions = 0;
while (match(COMMA)) {
next();
elisions++;
}
if (match(CLOSEBRACKET)) {
JSTokenLocation location(tokenLocation());
next(TreeBuilder::DontBuildStrings);
return context.createArray(location, elisions, elementList);
}
if (UNLIKELY(match(DOTDOTDOT))) {
auto spreadLocation = m_token.m_location;
auto start = m_token.m_startPosition;
auto divot = m_token.m_endPosition;
next();
TreeExpression elem = parseAssignmentExpressionOrPropagateErrorClass(context);
failIfFalse(elem, "Cannot parse subject of a spread operation");
auto spread = context.createSpreadExpression(spreadLocation, elem, start, divot, m_lastTokenEndPosition);
tail = context.createElementList(tail, elisions, spread);
continue;
}
TreeExpression elem = parseAssignmentExpressionOrPropagateErrorClass(context);
failIfFalse(elem, "Cannot parse array literal element");
tail = context.createElementList(tail, elisions, elem);
}
JSTokenLocation location(tokenLocation());
if (!consume(CLOSEBRACKET)) {
failIfFalse(match(DOTDOTDOT), "Expected either a closing ']' or a ',' following an array element");
semanticFail("The '...' operator should come before a target expression");
}
m_parserState.nonLHSCount = oldNonLHSCount;
return context.createArray(location, elementList);
}
template <typename LexerType>
template <class TreeBuilder> TreeClassExpression Parser<LexerType>::parseClassExpression(TreeBuilder& context)
{
ASSERT(match(CLASSTOKEN));
ParserClassInfo<TreeBuilder> info;
info.className = &m_vm.propertyNames->nullIdentifier;
return parseClass(context, FunctionNameRequirements::None, info);
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseFunctionExpression(TreeBuilder& context)
{
ASSERT(match(FUNCTION));
JSTokenLocation location(tokenLocation());
unsigned functionKeywordStart = tokenStart();
next();
ParserFunctionInfo<TreeBuilder> functionInfo;
functionInfo.name = &m_vm.propertyNames->nullIdentifier;
SourceParseMode parseMode = SourceParseMode::NormalFunctionMode;
if (consume(TIMES))
parseMode = SourceParseMode::GeneratorWrapperFunctionMode;
failIfFalse((parseFunctionInfo(context, FunctionNameRequirements::None, parseMode, false, ConstructorKind::None, SuperBinding::NotNeeded, functionKeywordStart, functionInfo, FunctionDefinitionType::Expression)), "Cannot parse function expression");
return context.createFunctionExpr(location, functionInfo);
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseAsyncFunctionExpression(TreeBuilder& context)
{
ASSERT(match(FUNCTION));
JSTokenLocation location(tokenLocation());
unsigned functionKeywordStart = tokenStart();
next();
SourceParseMode parseMode = SourceParseMode::AsyncFunctionMode;
if (consume(TIMES))
parseMode = SourceParseMode::AsyncGeneratorWrapperFunctionMode;
ParserFunctionInfo<TreeBuilder> functionInfo;
functionInfo.name = &m_vm.propertyNames->nullIdentifier;
failIfFalse(parseFunctionInfo(context, FunctionNameRequirements::None, parseMode, false, ConstructorKind::None, SuperBinding::NotNeeded, functionKeywordStart, functionInfo, FunctionDefinitionType::Expression), parseMode == SourceParseMode::AsyncFunctionMode ? "Cannot parse async function expression" : "Cannot parse async generator function expression");
return context.createFunctionExpr(location, functionInfo);
}
template <typename LexerType>
template <class TreeBuilder> typename TreeBuilder::TemplateString Parser<LexerType>::parseTemplateString(TreeBuilder& context, bool isTemplateHead, typename LexerType::RawStringsBuildMode rawStringsBuildMode, bool& elementIsTail)
{
if (isTemplateHead)
ASSERT(match(BACKQUOTE));
else
matchOrFail(CLOSEBRACE, "Expected a closing '}' following an expression in template literal");
// Re-scan the token to recognize it as Template Element.
m_token.m_type = m_lexer->scanTemplateString(&m_token, rawStringsBuildMode);
matchOrFail(TEMPLATE, "Expected an template element");
const Identifier* cooked = m_token.m_data.cooked;
const Identifier* raw = m_token.m_data.raw;
elementIsTail = m_token.m_data.isTail;
JSTokenLocation location(tokenLocation());
next();
return context.createTemplateString(location, cooked, raw);
}
template <typename LexerType>
template <class TreeBuilder> typename TreeBuilder::TemplateLiteral Parser<LexerType>::parseTemplateLiteral(TreeBuilder& context, typename LexerType::RawStringsBuildMode rawStringsBuildMode)
{
ASSERT(match(BACKQUOTE));
JSTokenLocation location(tokenLocation());
bool elementIsTail = false;
auto headTemplateString = parseTemplateString(context, true, rawStringsBuildMode, elementIsTail);
failIfFalse(headTemplateString, "Cannot parse head template element");
typename TreeBuilder::TemplateStringList templateStringList = context.createTemplateStringList(headTemplateString);
typename TreeBuilder::TemplateStringList templateStringTail = templateStringList;
if (elementIsTail)
return context.createTemplateLiteral(location, templateStringList);
failIfTrue(match(CLOSEBRACE), "Template literal expression cannot be empty");
TreeExpression expression = parseExpression(context);
failIfFalse(expression, "Cannot parse expression in template literal");
typename TreeBuilder::TemplateExpressionList templateExpressionList = context.createTemplateExpressionList(expression);
typename TreeBuilder::TemplateExpressionList templateExpressionTail = templateExpressionList;
auto templateString = parseTemplateString(context, false, rawStringsBuildMode, elementIsTail);
failIfFalse(templateString, "Cannot parse template element");
templateStringTail = context.createTemplateStringList(templateStringTail, templateString);
while (!elementIsTail) {
failIfTrue(match(CLOSEBRACE), "Template literal expression cannot be empty");
TreeExpression expression = parseExpression(context);
failIfFalse(expression, "Cannot parse expression in template literal");
templateExpressionTail = context.createTemplateExpressionList(templateExpressionTail, expression);
auto templateString = parseTemplateString(context, false, rawStringsBuildMode, elementIsTail);
failIfFalse(templateString, "Cannot parse template element");
templateStringTail = context.createTemplateStringList(templateStringTail, templateString);
}
return context.createTemplateLiteral(location, templateStringList, templateExpressionList);
}
template <class LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::createResolveAndUseVariable(TreeBuilder& context, const Identifier* ident, bool isEval, const JSTextPosition& start, const JSTokenLocation& location)
{
currentScope()->useVariable(ident, isEval);
m_parserState.lastIdentifier = ident;
return context.createResolve(location, *ident, start, lastTokenEndPosition());
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parsePrimaryExpression(TreeBuilder& context)
{
failIfStackOverflow();
switch (m_token.m_type) {
case FUNCTION:
return parseFunctionExpression(context);
case CLASSTOKEN:
return parseClassExpression(context);
case OPENBRACE:
return parseObjectLiteral(context);
case OPENBRACKET:
return parseArrayLiteral(context);
case OPENPAREN: {
next();
int oldNonLHSCount = m_parserState.nonLHSCount;
TreeExpression result = parseExpression(context);
m_parserState.nonLHSCount = oldNonLHSCount;
handleProductionOrFail(CLOSEPAREN, ")", "end", "compound expression");
return result;
}
case THISTOKEN: {
JSTokenLocation location(tokenLocation());
next();
if (currentScope()->isArrowFunction())
currentScope()->setInnerArrowFunctionUsesThis();
return context.createThisExpr(location);
}
case AWAIT:
if (m_parserState.functionParsePhase == FunctionParsePhase::Parameters)
semanticFailIfFalse(m_parserState.allowAwait, "Cannot use 'await' within a parameter default expression");
else if (currentFunctionScope()->isAsyncFunctionBoundary())
return parseAwaitExpression(context);
goto identifierExpression;
case IDENT: {
if (UNLIKELY(*m_token.m_data.ident == m_vm.propertyNames->async && !m_token.m_data.escaped)) {
JSTextPosition start = tokenStartPosition();
const Identifier* ident = m_token.m_data.ident;
JSTokenLocation location(tokenLocation());
next();
if (match(FUNCTION) && !m_lexer->hasLineTerminatorBeforeToken())
return parseAsyncFunctionExpression(context);
// Avoid using variable if it is an arrow function parameter
if (UNLIKELY(match(ARROWFUNCTION)))
return 0;
const bool isEval = false;
return createResolveAndUseVariable(context, ident, isEval, start, location);
}
if (UNLIKELY(m_parserState.isParsingClassFieldInitializer))
failIfTrue(*m_token.m_data.ident == m_vm.propertyNames->arguments, "Cannot reference 'arguments' in class field initializer");
identifierExpression:
JSTextPosition start = tokenStartPosition();
const Identifier* ident = m_token.m_data.ident;
if (UNLIKELY(currentScope()->evalContextType() == EvalContextType::InstanceFieldEvalContext))
failIfTrue(*ident == m_vm.propertyNames->arguments, "arguments is not valid in this context");
JSTokenLocation location(tokenLocation());
next();
// Avoid using variable if it is an arrow function parameter
if (UNLIKELY(match(ARROWFUNCTION)))
return 0;
return createResolveAndUseVariable(context, ident, *ident == m_vm.propertyNames->eval, start, location);
}
case BIGINT: {
const Identifier* ident = m_token.m_data.bigIntString;
uint8_t radix = m_token.m_data.radix;
JSTokenLocation location(tokenLocation());
next();
return context.createBigInt(location, ident, radix);
}
case STRING: {
const Identifier* ident = m_token.m_data.ident;
JSTokenLocation location(tokenLocation());
next();
return context.createString(location, ident);
}
case DOUBLE: {
double d = m_token.m_data.doubleValue;
JSTokenLocation location(tokenLocation());
next();
return context.createDoubleExpr(location, d);
}
case INTEGER: {
double d = m_token.m_data.doubleValue;
JSTokenLocation location(tokenLocation());
next();
return context.createIntegerExpr(location, d);
}
case NULLTOKEN: {
JSTokenLocation location(tokenLocation());
next();
return context.createNull(location);
}
case TRUETOKEN: {
JSTokenLocation location(tokenLocation());
next();
return context.createBoolean(location, true);
}
case FALSETOKEN: {
JSTokenLocation location(tokenLocation());
next();
return context.createBoolean(location, false);
}
case DIVEQUAL:
case DIVIDE: {
/* regexp */
if (match(DIVEQUAL))
m_token.m_type = m_lexer->scanRegExp(&m_token, '=');
else
m_token.m_type = m_lexer->scanRegExp(&m_token);
matchOrFail(REGEXP, "Invalid regular expression");
const Identifier* pattern = m_token.m_data.pattern;
const Identifier* flags = m_token.m_data.flags;
JSTextPosition start = tokenStartPosition();
JSTokenLocation location(tokenLocation());
next();
TreeExpression re = context.createRegExp(location, *pattern, *flags, start);
if (!re) {
Yarr::ErrorCode errorCode = Yarr::checkSyntax(pattern->string(), flags->string());
regexFail(Yarr::errorMessage(errorCode));
}
return re;
}
case BACKQUOTE:
return parseTemplateLiteral(context, LexerType::RawStringsBuildMode::DontBuildRawStrings);
case YIELD:
if (!strictMode() && !currentScope()->isGenerator())
goto identifierExpression;
failDueToUnexpectedToken();
case LET:
if (!strictMode())
goto identifierExpression;
FALLTHROUGH;
default:
failDueToUnexpectedToken();
}
}
template <typename LexerType>
template <class TreeBuilder> TreeArguments Parser<LexerType>::parseArguments(TreeBuilder& context)
{
consumeOrFailWithFlags(OPENPAREN, TreeBuilder::DontBuildStrings, "Expected opening '(' at start of argument list");
JSTokenLocation location(tokenLocation());
if (match(CLOSEPAREN)) {
next(TreeBuilder::DontBuildStrings);
return context.createArguments();
}
auto argumentsStart = m_token.m_startPosition;
auto argumentsDivot = m_token.m_endPosition;
int initialAssignments = m_parserState.assignmentCount;
ArgumentType argType = ArgumentType::Normal;
TreeExpression firstArg = parseArgument(context, argType);
failIfFalse(firstArg, "Cannot parse function argument");
semanticFailIfTrue(match(DOTDOTDOT), "The '...' operator should come before the target expression");
bool hasSpread = false;
if (argType == ArgumentType::Spread)
hasSpread = true;
TreeArgumentsList argList = context.createArgumentsList(location, firstArg);
TreeArgumentsList tail = argList;
while (match(COMMA)) {
JSTokenLocation argumentLocation(tokenLocation());
next(TreeBuilder::DontBuildStrings);
if (UNLIKELY(match(CLOSEPAREN)))
break;
TreeExpression arg = parseArgument(context, argType);
propagateError();
semanticFailIfTrue(match(DOTDOTDOT), "The '...' operator should come before the target expression");
if (argType == ArgumentType::Spread)
hasSpread = true;
tail = context.createArgumentsList(argumentLocation, tail, arg);
}
handleProductionOrFail2(CLOSEPAREN, ")", "end", "argument list");
if (hasSpread) {
TreeExpression spreadArray = context.createSpreadExpression(location, context.createArray(location, context.createElementList(argList)), argumentsStart, argumentsDivot, m_lastTokenEndPosition);
return context.createArguments(context.createArgumentsList(location, spreadArray), initialAssignments != m_parserState.assignmentCount);
}
return context.createArguments(argList, initialAssignments != m_parserState.assignmentCount);
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseArgument(TreeBuilder& context, ArgumentType& type)
{
if (UNLIKELY(match(DOTDOTDOT))) {
JSTokenLocation spreadLocation(tokenLocation());
auto start = m_token.m_startPosition;
auto divot = m_token.m_endPosition;
next();
TreeExpression spreadExpr = parseAssignmentExpression(context);
propagateError();
auto end = m_lastTokenEndPosition;
type = ArgumentType::Spread;
return context.createSpreadExpression(spreadLocation, spreadExpr, start, divot, end);
}
type = ArgumentType::Normal;
return parseAssignmentExpression(context);
}
template <typename TreeBuilder, typename ParserType, typename = typename std::enable_if<std::is_same<TreeBuilder, ASTBuilder>::value>::type>
static inline void recordCallOrApplyDepth(ParserType* parser, VM& vm, Optional<typename ParserType::CallOrApplyDepthScope>& callOrApplyDepthScope, ExpressionNode* expression)
{
if (expression->isDotAccessorNode()) {
DotAccessorNode* dot = static_cast<DotAccessorNode*>(expression);
bool isCallOrApply = dot->identifier() == vm.propertyNames->builtinNames().callPublicName() || dot->identifier() == vm.propertyNames->builtinNames().applyPublicName();
if (isCallOrApply)
callOrApplyDepthScope.emplace(parser);
}
}
template <typename TreeBuilder, typename ParserType, typename = typename std::enable_if<std::is_same<TreeBuilder, SyntaxChecker>::value>::type>
static inline void recordCallOrApplyDepth(ParserType*, VM&, Optional<typename ParserType::CallOrApplyDepthScope>&, SyntaxChecker::Expression)
{
}
template <typename LexerType>
bool Parser<LexerType>::usePrivateName(const Identifier* ident)
{
if (m_lexer->isReparsingFunction())
return true;
if (auto maybeCurrent = findPrivateNameScope()) {
ScopeRef current = maybeCurrent.value();
if (!current->hasPrivateName(*ident))
current->usePrivateName(*ident);
return true;
}
return false;
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseMemberExpression(TreeBuilder& context)
{
TreeExpression base = 0;
JSTextPosition expressionStart = tokenStartPosition();
int newCount = 0;
JSTokenLocation startLocation = tokenLocation();
JSTokenLocation lastNewTokenLocation;
while (match(NEW)) {
lastNewTokenLocation = tokenLocation();
next();
newCount++;
}
JSTokenLocation location = tokenLocation();
bool baseIsSuper = match(SUPER);
bool previousBaseWasSuper = false;
bool baseIsImport = match(IMPORT);
bool baseIsNewTarget = false;
if (newCount && match(DOT)) {
next();
if (matchContextualKeyword(m_vm.propertyNames->target)) {
ScopeRef closestOrdinaryFunctionScope = closestParentOrdinaryFunctionNonLexicalScope();
bool isClassFieldInitializer = m_parserState.isParsingClassFieldInitializer;
bool isFunctionEvalContextType = m_isInsideOrdinaryFunction && (closestOrdinaryFunctionScope->evalContextType() == EvalContextType::FunctionEvalContext || closestOrdinaryFunctionScope->evalContextType() == EvalContextType::InstanceFieldEvalContext);
semanticFailIfFalse(currentScope()->isFunction() || isFunctionEvalContextType || isClassFieldInitializer, "new.target is only valid inside functions");
baseIsNewTarget = true;
if (currentScope()->isArrowFunction()) {
semanticFailIfFalse(!closestOrdinaryFunctionScope->isGlobalCodeScope() || isFunctionEvalContextType || isClassFieldInitializer, "new.target is not valid inside arrow functions in global code");
currentScope()->setInnerArrowFunctionUsesNewTarget();
}
ASSERT(lastNewTokenLocation.line);
base = context.createNewTargetExpr(lastNewTokenLocation);
newCount--;
next();
} else {
failIfTrue(match(IDENT), "\"new.\" can only followed with target");
failDueToUnexpectedToken();
}
}
bool baseIsAsyncKeyword = false;
if (baseIsSuper) {
ScopeRef closestOrdinaryFunctionScope = closestParentOrdinaryFunctionNonLexicalScope();
ScopeRef classScope = closestClassScopeOrTopLevelScope();
bool isClassFieldInitializer = classScope.index() > closestOrdinaryFunctionScope.index();
semanticFailIfFalse(currentScope()->isFunction() || isClassFieldInitializer || (closestOrdinaryFunctionScope->isEvalContext() && closestOrdinaryFunctionScope->expectedSuperBinding() == SuperBinding::Needed), "super is not valid in this context");
base = context.createSuperExpr(location);
next();
failIfTrue(match(OPENPAREN) && currentScope()->evalContextType() == EvalContextType::InstanceFieldEvalContext, "super call is not valid in this context");
ScopeRef functionScope = currentFunctionScope();
if (!functionScope->setNeedsSuperBinding()) {
// It unnecessary to check of using super during reparsing one more time. Also it can lead to syntax error
// in case of arrow function because during reparsing we don't know whether we currently parse the arrow function
// inside of the constructor or method.
if (!m_lexer->isReparsingFunction()) {
SuperBinding functionSuperBinding = !functionScope->isArrowFunction() && !closestOrdinaryFunctionScope->isEvalContext()
? functionScope->expectedSuperBinding()
: closestOrdinaryFunctionScope->expectedSuperBinding();
semanticFailIfTrue(functionSuperBinding == SuperBinding::NotNeeded && !isClassFieldInitializer, "super is not valid in this context");
}
}
} else if (baseIsImport) {
next();
JSTextPosition expressionEnd = lastTokenEndPosition();
if (consume(DOT)) {
if (matchContextualKeyword(m_vm.propertyNames->builtinNames().metaPublicName())) {
semanticFailIfFalse(m_scriptMode == JSParserScriptMode::Module, "import.meta is only valid inside modules");
base = context.createImportMetaExpr(location, createResolveAndUseVariable(context, &m_vm.propertyNames->metaPrivateName, false, expressionStart, location));
next();
} else {
failIfTrue(match(IDENT), "\"import.\" can only followed with meta");
failDueToUnexpectedToken();
}
} else {
semanticFailIfTrue(newCount, "Cannot use new with import");
consumeOrFail(OPENPAREN, "import call expects exactly one argument");
TreeExpression expr = parseAssignmentExpression(context);
failIfFalse(expr, "Cannot parse expression");
consumeOrFail(CLOSEPAREN, "import call expects exactly one argument");
base = context.createImportExpr(location, expr, expressionStart, expressionEnd, lastTokenEndPosition());
}
} else if (!baseIsNewTarget) {
const bool isAsync = matchContextualKeyword(m_vm.propertyNames->async);
base = parsePrimaryExpression(context);
failIfFalse(base, "Cannot parse base expression");
if (UNLIKELY(isAsync && context.isResolve(base) && !m_lexer->hasLineTerminatorBeforeToken())) {
if (matchSpecIdentifier()) {
// AsyncArrowFunction
forceClassifyExpressionError(ErrorIndicatesAsyncArrowFunction);
failDueToUnexpectedToken();
}
baseIsAsyncKeyword = true;
}
}
failIfFalse(base, "Cannot parse base expression");
do {
TreeExpression optionalChainBase = 0;
JSTokenLocation optionalChainLocation;
JSTokenType type = m_token.m_type;
if (match(QUESTIONDOT)) {
semanticFailIfTrue(newCount, "Cannot call constructor in an optional chain");
semanticFailIfTrue(baseIsSuper, "Cannot use super as the base of an optional chain");
optionalChainBase = base;
optionalChainLocation = tokenLocation();
SavePoint savePoint = createSavePoint(context);
next();
if (match(OPENBRACKET) || match(OPENPAREN) || match(BACKQUOTE))
type = m_token.m_type;
else {
type = DOT;
restoreSavePoint(context, savePoint);
}
}
while (true) {
location = tokenLocation();
switch (type) {
case OPENBRACKET: {
m_parserState.nonTrivialExpressionCount++;
JSTextPosition expressionEnd = lastTokenEndPosition();
next();
int nonLHSCount = m_parserState.nonLHSCount;
int initialAssignments = m_parserState.assignmentCount;
TreeExpression property = parseExpression(context);
failIfFalse(property, "Cannot parse subscript expression");
base = context.createBracketAccess(startLocation, base, property, initialAssignments != m_parserState.assignmentCount, expressionStart, expressionEnd, tokenEndPosition());
if (UNLIKELY(baseIsSuper && currentScope()->isArrowFunction()))
currentFunctionScope()->setInnerArrowFunctionUsesSuperProperty();
handleProductionOrFail(CLOSEBRACKET, "]", "end", "subscript expression");
m_parserState.nonLHSCount = nonLHSCount;
break;
}
case OPENPAREN: {
if (baseIsSuper)
failIfTrue(m_parserState.isParsingClassFieldInitializer, "super call is not valid in class field initializer context");
m_parserState.nonTrivialExpressionCount++;
int nonLHSCount = m_parserState.nonLHSCount;
if (newCount) {
newCount--;
semanticFailIfTrue(baseIsSuper, "Cannot use new with super call");
JSTextPosition expressionEnd = lastTokenEndPosition();
TreeArguments arguments = parseArguments(context);
failIfFalse(arguments, "Cannot parse call arguments");
base = context.createNewExpr(location, base, arguments, expressionStart, expressionEnd, lastTokenEndPosition());
} else {
size_t usedVariablesSize = currentScope()->currentUsedVariablesSize();
JSTextPosition expressionEnd = lastTokenEndPosition();
Optional<CallOrApplyDepthScope> callOrApplyDepthScope;
recordCallOrApplyDepth<TreeBuilder>(this, m_vm, callOrApplyDepthScope, base);
TreeArguments arguments = parseArguments(context);
if (baseIsAsyncKeyword && (!arguments || match(ARROWFUNCTION))) {
currentScope()->revertToPreviousUsedVariables(usedVariablesSize);
forceClassifyExpressionError(ErrorIndicatesAsyncArrowFunction);
failDueToUnexpectedToken();
}
failIfFalse(arguments, "Cannot parse call arguments");
if (baseIsSuper) {
ScopeRef functionScope = currentFunctionScope();
if (!functionScope->setHasDirectSuper()) {
// It unnecessary to check of using super during reparsing one more time. Also it can lead to syntax error
// in case of arrow function because during reparsing we don't know whether we currently parse the arrow function
// inside of the constructor or method.
if (!m_lexer->isReparsingFunction()) {
ScopeRef closestOrdinaryFunctionScope = closestParentOrdinaryFunctionNonLexicalScope();
ConstructorKind functionConstructorKind = !functionScope->isArrowFunction() && !closestOrdinaryFunctionScope->isEvalContext()
? functionScope->constructorKind()
: closestOrdinaryFunctionScope->constructorKind();
semanticFailIfTrue(functionConstructorKind == ConstructorKind::None, "super is not valid in this context");
semanticFailIfTrue(functionConstructorKind != ConstructorKind::Extends, "super is not valid in this context");
}
}
if (currentScope()->isArrowFunction())
functionScope->setInnerArrowFunctionUsesSuperCall();
}
bool isOptionalCall = optionalChainLocation.endOffset == static_cast<unsigned>(expressionEnd.offset);
base = context.makeFunctionCallNode(startLocation, base, previousBaseWasSuper, arguments, expressionStart,
expressionEnd, lastTokenEndPosition(), callOrApplyDepthScope ? callOrApplyDepthScope->distanceToInnermostChild() : 0, isOptionalCall);
if (isOptionalCall)
optionalChainBase = base;
}
m_parserState.nonLHSCount = nonLHSCount;
break;
}
case DOT: {
m_parserState.nonTrivialExpressionCount++;
JSTextPosition expressionEnd = lastTokenEndPosition();
nextExpectIdentifier(TreeBuilder::DontBuildKeywords | LexerFlags::IgnoreReservedWords);
const Identifier* ident = m_token.m_data.ident;
auto type = DotType::Name;
if (match(PRIVATENAME)) {
ASSERT(ident);
failIfTrue(baseIsSuper, "Cannot access private names from super");
if (UNLIKELY(currentScope()->evalContextType() == EvalContextType::InstanceFieldEvalContext))
semanticFailIfFalse(currentScope()->hasPrivateName(*ident), "Cannot reference undeclared private field '", ident->impl(), "'");
semanticFailIfFalse(usePrivateName(ident), "Cannot reference private names outside of class");
m_parserState.lastPrivateName = ident;
currentScope()->useVariable(ident, false);
type = DotType::PrivateField;
m_token.m_type = IDENT;
}
matchOrFail(IDENT, "Expected a property name after ", optionalChainBase ? "'?.'" : "'.'");
base = context.createDotAccess(startLocation, base, ident, type, expressionStart, expressionEnd, tokenEndPosition());
if (UNLIKELY(baseIsSuper && currentScope()->isArrowFunction()))
currentFunctionScope()->setInnerArrowFunctionUsesSuperProperty();
next();
break;
}
case BACKQUOTE: {
semanticFailIfTrue(optionalChainBase, "Cannot use tagged templates in an optional chain");
semanticFailIfTrue(baseIsSuper, "Cannot use super as tag for tagged templates");
JSTextPosition expressionEnd = lastTokenEndPosition();
int nonLHSCount = m_parserState.nonLHSCount;
typename TreeBuilder::TemplateLiteral templateLiteral = parseTemplateLiteral(context, LexerType::RawStringsBuildMode::BuildRawStrings);
failIfFalse(templateLiteral, "Cannot parse template literal");
base = context.createTaggedTemplate(startLocation, base, templateLiteral, expressionStart, expressionEnd, lastTokenEndPosition());
m_parserState.nonLHSCount = nonLHSCount;
m_seenTaggedTemplate = true;
break;
}
default:
goto endOfChain;
}
previousBaseWasSuper = baseIsSuper;
baseIsSuper = false;
type = m_token.m_type;
}
endOfChain:
if (optionalChainBase)
base = context.createOptionalChain(optionalChainLocation, optionalChainBase, base, !match(QUESTIONDOT));
} while (match(QUESTIONDOT));
semanticFailIfTrue(baseIsSuper, newCount ? "Cannot use new with super call" : "super is not valid in this context");
while (newCount--)
base = context.createNewExpr(location, base, expressionStart, lastTokenEndPosition());
return base;
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseArrowFunctionExpression(TreeBuilder& context, bool isAsync)
{
JSTokenLocation location;
unsigned functionKeywordStart = tokenStart();
location = tokenLocation();
ParserFunctionInfo<TreeBuilder> info;
info.name = &m_vm.propertyNames->nullIdentifier;
SourceParseMode parseMode = isAsync ? SourceParseMode::AsyncArrowFunctionMode : SourceParseMode::ArrowFunctionMode;
failIfFalse((parseFunctionInfo(context, FunctionNameRequirements::Unnamed, parseMode, true, ConstructorKind::None, SuperBinding::NotNeeded, functionKeywordStart, info, FunctionDefinitionType::Expression)), "Cannot parse arrow function expression");
return context.createArrowFunctionExpr(location, info);
}
static const char* operatorString(bool prefix, unsigned tok)
{
switch (tok) {
case MINUSMINUS:
case AUTOMINUSMINUS:
return prefix ? "prefix-decrement" : "decrement";
case PLUSPLUS:
case AUTOPLUSPLUS:
return prefix ? "prefix-increment" : "increment";
case EXCLAMATION:
return "logical-not";
case TILDE:
return "bitwise-not";
case TYPEOF:
return "typeof";
case VOIDTOKEN:
return "void";
case DELETETOKEN:
return "delete";
}
RELEASE_ASSERT_NOT_REACHED();
return "error";
}
template <typename LexerType>
template <class TreeBuilder> TreeExpression Parser<LexerType>::parseUnaryExpression(TreeBuilder& context)
{
typename TreeBuilder::UnaryExprContext unaryExprContext(context);
AllowInOverride allowInOverride(this);
int tokenStackDepth = 0;
bool hasPrefixUpdateOp = false;
unsigned lastOperator = 0;
if (UNLIKELY(match(AWAIT) && currentFunctionScope()->isAsyncFunctionBoundary()))
return parseAwaitExpression(context);
JSTokenLocation location(tokenLocation());
int oldTokenStackDepth = context.unaryTokenStackDepth();
auto scopeExit = makeScopeExit([&] {
ASSERT_UNUSED(oldTokenStackDepth, oldTokenStackDepth <= context.unaryTokenStackDepth());
});
while (isUnaryOp(m_token.m_type)) {
semanticFailIfTrue(hasPrefixUpdateOp, "The ", operatorString(true, lastOperator), " operator requires a reference expression");
if (isUpdateOp(m_token.m_type))
hasPrefixUpdateOp = true;
lastOperator = m_token.m_type;
m_parserState.nonLHSCount++;
context.appendUnaryToken(tokenStackDepth, m_token.m_type, tokenStartPosition());
next();
m_parserState.nonTrivialExpressionCount++;
}
JSTextPosition subExprStart = tokenStartPosition();
ASSERT(subExprStart.offset >= subExprStart.lineStartOffset);
TreeExpression expr = parseMemberExpression(context);
if (!expr) {
if (lastOperator)
failWithMessage("Cannot parse subexpression of ", operatorString(true, lastOperator), "operator");
failWithMessage("Cannot parse member expression");
}
if constexpr (std::is_same_v<TreeBuilder, ASTBuilder>)
ASSERT(oldTokenStackDepth + tokenStackDepth == context.unaryTokenStackDepth());
if (isUpdateOp(static_cast<JSTokenType>(lastOperator))) {
semanticFailIfTrue(context.isMetaProperty(expr), metaPropertyName(context, expr), " can't come after a prefix operator");
semanticFailIfFalse(isSimpleAssignmentTarget(context, expr), "Prefix ", lastOperator == PLUSPLUS ? "++" : "--", " operator applied to value that is not a reference");
}
bool isEvalOrArguments = false;
if (strictMode()) {
if (context.isResolve(expr))
isEvalOrArguments = *m_parserState.lastIdentifier == m_vm.propertyNames->eval || *m_parserState.lastIdentifier == m_vm.propertyNames->arguments;
}
failIfTrueIfStrict(isEvalOrArguments && hasPrefixUpdateOp, "Cannot modify '", m_parserState.lastIdentifier->impl(), "' in strict mode");
switch (m_token.m_type) {
case PLUSPLUS:
semanticFailIfTrue(context.isMetaProperty(expr), metaPropertyName(context, expr), " can't come before a postfix operator");
semanticFailIfFalse(isSimpleAssignmentTarget(context, expr), "Postfix ++ operator applied to value that is not a reference");
m_parserState.nonTrivialExpressionCount++;
m_parserState.nonLHSCount++;
expr = context.makePostfixNode(location, expr, Operator::PlusPlus, subExprStart, lastTokenEndPosition(), tokenEndPosition());
m_parserState.assignmentCount++;
failIfTrueIfStrict(isEvalOrArguments, "Cannot modify '", m_parserState.lastIdentifier->impl(), "' in strict mode");
semanticFailIfTrue(hasPrefixUpdateOp, "The ", operatorString(false, lastOperator), " operator requires a reference expression");
next();
break;
case MINUSMINUS:
semanticFailIfTrue(context.isMetaProperty(expr), metaPropertyName(context, expr), " can't come before a postfix operator");
semanticFailIfFalse(isSimpleAssignmentTarget(context, expr), "Postfix -- operator applied to value that is not a reference");
m_parserState.nonTrivialExpressionCount++;
m_parserState.nonLHSCount++;
expr = context.makePostfixNode(location, expr, Operator::MinusMinus, subExprStart, lastTokenEndPosition(), tokenEndPosition());
m_parserState.assignmentCount++;
failIfTrueIfStrict(isEvalOrArguments, "'", m_parserState.lastIdentifier->impl(), "' cannot be modified in strict mode");
semanticFailIfTrue(hasPrefixUpdateOp, "The ", operatorString(false, lastOperator), " operator requires a reference expression");
next();
break;
default:
break;
}
JSTextPosition end = lastTokenEndPosition();
while (tokenStackDepth) {
subExprStart = context.unaryTokenStackLastStart(tokenStackDepth);
auto tokenType = context.unaryTokenStackLastType(tokenStackDepth);
switch (tokenType) {
case EXCLAMATION:
expr = context.createLogicalNot(location, expr);
break;
case TILDE:
expr = context.makeBitwiseNotNode(location, expr);
break;
case MINUS:
expr = context.makeNegateNode(location, expr);
break;
case PLUS:
expr = context.createUnaryPlus(location, expr);
break;
case PLUSPLUS:
case AUTOPLUSPLUS:
ASSERT(isSimpleAssignmentTarget(context, expr));
expr = context.makePrefixNode(location, expr, Operator::PlusPlus, subExprStart, subExprStart + 2, end);
m_parserState.assignmentCount++;
break;
case MINUSMINUS:
case AUTOMINUSMINUS:
ASSERT(isSimpleAssignmentTarget(context, expr));
expr = context.makePrefixNode(location, expr, Operator::MinusMinus, subExprStart, subExprStart + 2, end);
m_parserState.assignmentCount++;
break;
case TYPEOF:
expr = context.makeTypeOfNode(location, expr);
break;
case VOIDTOKEN:
expr = context.createVoid(location, expr);
break;
case DELETETOKEN:
failIfTrueIfStrict(context.isResolve(expr), "Cannot delete unqualified property '", m_parserState.lastIdentifier->impl(), "' in strict mode");
semanticFailIfTrue(context.isPrivateLocation(expr), "Cannot delete private field ", m_parserState.lastPrivateName->impl());
expr = context.makeDeleteNode(location, expr, context.unaryTokenStackLastStart(tokenStackDepth), end, end);
break;
default:
// If we get here something has gone horribly horribly wrong
CRASH();
}
context.unaryTokenStackRemoveLast(tokenStackDepth);
}
return expr;
}
template <typename LexerType> void Parser<LexerType>::printUnexpectedTokenText(WTF::PrintStream& out)
{
switch (m_token.m_type) {
case EOFTOK:
out.print("Unexpected end of script");
return;
case UNTERMINATED_IDENTIFIER_ESCAPE_ERRORTOK:
case UNTERMINATED_IDENTIFIER_UNICODE_ESCAPE_ERRORTOK:
out.print("Incomplete unicode escape in identifier: '", getToken(), "'");
return;
case UNTERMINATED_MULTILINE_COMMENT_ERRORTOK:
out.print("Unterminated multiline comment");
return;
case UNTERMINATED_NUMERIC_LITERAL_ERRORTOK:
out.print("Unterminated numeric literal '", getToken(), "'");
return;
case UNTERMINATED_STRING_LITERAL_ERRORTOK:
out.print("Unterminated string literal '", getToken(), "'");
return;
case INVALID_IDENTIFIER_ESCAPE_ERRORTOK:
out.print("Invalid escape in identifier: '", getToken(), "'");
return;
case ESCAPED_KEYWORD:
out.print("Unexpected escaped characters in keyword token: '", getToken(), "'");
return;
case INVALID_IDENTIFIER_UNICODE_ESCAPE_ERRORTOK:
out.print("Invalid unicode escape in identifier: '", getToken(), "'");
return;
case INVALID_NUMERIC_LITERAL_ERRORTOK:
out.print("Invalid numeric literal: '", getToken(), "'");
return;
case UNTERMINATED_OCTAL_NUMBER_ERRORTOK:
out.print("Invalid use of octal: '", getToken(), "'");
return;
case INVALID_STRING_LITERAL_ERRORTOK:
out.print("Invalid string literal: '", getToken(), "'");
return;
case INVALID_UNICODE_ENCODING_ERRORTOK:
out.print("Invalid unicode encoding: '", getToken(), "'");
return;
case INVALID_IDENTIFIER_UNICODE_ERRORTOK:
out.print("Invalid unicode code point in identifier: '", getToken(), "'");
return;
case ERRORTOK:
out.print("Unrecognized token '", getToken(), "'");
return;
case STRING:
out.print("Unexpected string literal ", getToken());
return;
case INTEGER:
case DOUBLE:
out.print("Unexpected number '", getToken(), "'");
return;
case RESERVED_IF_STRICT:
out.print("Unexpected use of reserved word '", getToken(), "' in strict mode");
return;
case RESERVED:
out.print("Unexpected use of reserved word '", getToken(), "'");
return;
case INVALID_PRIVATE_NAME_ERRORTOK:
out.print("Invalid private name '", getToken(), "'");
return;
case PRIVATENAME:
out.print("Unexpected private name ", getToken());
return;
case AWAIT:
case IDENT:
out.print("Unexpected identifier '", getToken(), "'");
return;
default:
break;
}
if (m_token.m_type & KeywordTokenFlag) {
out.print("Unexpected keyword '", getToken(), "'");
return;
}
out.print("Unexpected token '", getToken(), "'");
}
// Instantiate the two flavors of Parser we need instead of putting most of this file in Parser.h
template class Parser<Lexer<LChar>>;
template class Parser<Lexer<UChar>>;
} // namespace JSC
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